This change aims to introduce the separation of the RegisterAllocator model,
using the initial prototype for RegisterAllocatorGreedy as proof of concept.

Summary:
- new flag, turbo-greedy-regalloc, enabling the new allocator. Default
  false.
- separated RegisterAllocator into a base type and two derived,
  RegisterAllocatorLinear (the one currently used in TurboFan) and
  RegisterAllocatorGreedy (the new one).
- initial, untested impementation for the greedy allocator.

BUG=

Review URL: https://codereview.chromium.org/1061923005

Cr-Commit-Position: refs/heads/master@{#28015}

Revert of Remove the weak list of views from array buffers (patchset #6 id:100001 of https://codereview.chromium.org/1094863002/)

Reason for revert:
I'm reverting this while working on the regression fix

Original issue's description:
> Remove the weak list of views from array buffers
>
> Instead, views have to check their array buffer for whether
> it's neutered or not.
>
> BUG=v8:3996
> R=hpayer@chromium.org,dslomov@chromium.org,verwaest@chromium.org
> LOG=n
>
> Committed: https://crrev.com/5ae083a05a6743d6cb91585f449539f7846a5d8c
> Cr-Commit-Position: refs/heads/master@{#27995}

TBR=dslomov@chromium.org,hpayer@chromium.org,verwaest@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:3996

Review URL: https://codereview.chromium.org/1061753008

Cr-Commit-Position: refs/heads/master@{#28014}

R=jarin@chromium.org,mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1100113002

Cr-Commit-Position: refs/heads/master@{#28013}

TBR=mstarzinger@chromium.org
NOTRY=true
BUG=v8:4055
LOG=N

Review URL: https://codereview.chromium.org/1098293002

Cr-Commit-Position: refs/heads/master@{#28012}

Revert of Revert of Always optimize for adding properties to native objects. (patchset #1 id:1 of https://codereview.chromium.org/1098223004/)

Reason for revert:
Test failure was not due to this.

Original issue's description:
> Revert of Always optimize for adding properties to native objects. (patchset #1 id:1 of https://codereview.chromium.org/1094383004/)
>
> Reason for revert:
> GC stress failure (custom snapshot)
>
> Original issue's description:
> > Always optimize for adding properties to native objects.
> >
> > R=jkummerow@chromium.org
> >
> > Committed: https://crrev.com/c715098e85b93def76c0b3f54290c811dea04f01
> > Cr-Commit-Position: refs/heads/master@{#28003}
>
> TBR=jkummerow@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
>
> Committed: https://crrev.com/bb6958ceff221e66adbc4581471a8ce1b41a4684
> Cr-Commit-Position: refs/heads/master@{#28009}

TBR=jkummerow@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1100123002

Cr-Commit-Position: refs/heads/master@{#28011}

Cr-Commit-Position: refs/heads/master@{#28010}

Revert of Always optimize for adding properties to native objects. (patchset #1 id:1 of https://codereview.chromium.org/1094383004/)

Reason for revert:
GC stress failure (custom snapshot)

Original issue's description:
> Always optimize for adding properties to native objects.
>
> R=jkummerow@chromium.org
>
> Committed: https://crrev.com/c715098e85b93def76c0b3f54290c811dea04f01
> Cr-Commit-Position: refs/heads/master@{#28003}

TBR=jkummerow@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1098223004

Cr-Commit-Position: refs/heads/master@{#28009}

Review URL: https://codereview.chromium.org/981203003

Cr-Commit-Position: refs/heads/master@{#28008}

BUG=

Review URL: https://codereview.chromium.org/1094243004

Cr-Commit-Position: refs/heads/master@{#28007}

this is necessary for the greedy allocator to use the relevant functions, as well as the sanity of someone looking at the code

BUG=

Review URL: https://codereview.chromium.org/1056063004

Cr-Commit-Position: refs/heads/master@{#28006}

R=marja@chromium.org,rossberg@chromium.org

Review URL: https://codereview.chromium.org/1065983005

Cr-Commit-Position: refs/heads/master@{#28005}

Review URL: https://codereview.chromium.org/1101683002

Cr-Commit-Position: refs/heads/master@{#28004}

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/1094383004

Cr-Commit-Position: refs/heads/master@{#28003}

R=bmeurer@chromium.org, mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1090303004

Cr-Commit-Position: refs/heads/master@{#28002}

Revert of Revert of [strong] checking of this & super in constructors (patchset #1 id:1 of https://codereview.chromium.org/1105453002/)

Reason for revert:
Was an infrastructure problem.

Original issue's description:
> Revert of [strong] checking of this & super in constructors (patchset #7 id:110001 of https://codereview.chromium.org/1024063002/)
>
> Reason for revert:
> [Sheriff] Breaks mac gc stress:
> http://build.chromium.org/p/client.v8/builders/V8%20Mac%20GC%20Stress/builds/1024
>
> Original issue's description:
> > [strong] checking of this & super in constructors
> >
> > R=dslomov@chromium.org, marja@chromium.org
> > BUG=v8:3956
> > LOG=N
> >
> > Enforces for constructors that
> > - the only use of 'super' is the super constructor call
> > - the only use of 'this' is a property assignment
> > - both of these must happen at the top-level of the body
> > - 'this' may only be assigned after the 'super' call
> > - 'return' may only be used after the last assignment to 'this'
> >
> > Not yet working for arrow functions (there might be deeper bugs with those).
> >
> > Committed: https://crrev.com/580d66bcda66220d2f3062ac58daf925436df74c
> > Cr-Commit-Position: refs/heads/master@{#27977}
>
> TBR=dslomov@chromium.org,marja@chromium.org,conradw@chromium.org,rossberg@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=v8:3956

TBR=dslomov@chromium.org,marja@chromium.org,conradw@chromium.org,rossberg@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:3956

Review URL: https://codereview.chromium.org/1073103004

Cr-Commit-Position: refs/heads/master@{#28001}

Revert of Revert of Protect the emptiness of Array prototype elements with a PropertyCell. (patchset #1 id:1 of https://codereview.chromium.org/1099203004/)

Reason for revert:
This was probably an infrastructure problem caused by the mac ninja/goma switch.

Original issue's description:
> Revert of Protect the emptiness of Array prototype elements with a PropertyCell. (patchset #7 id:120001 of https://codereview.chromium.org/1092043002/)
>
> Reason for revert:
> MAC GCSTRESS failure on new test.
>
> Original issue's description:
> > Protect the emptiness of Array prototype elements with a PropertyCell.
> >
> > Not just emptiness, but also a particular structure.
> >
> > BUG=v8:4044
> > LOG=N
>
> TBR=jkummerow@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=v8:4044

TBR=jkummerow@chromium.org,mvstanton@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4044

Review URL: https://codereview.chromium.org/1052253003

Cr-Commit-Position: refs/heads/master@{#28000}

Revert of Revert of [es6] don't throw if argument is non-object (O.freeze, O.seal, O.preventExtensions) (patchset #1 id:1 of https://codereview.chromium.org/1103473003/)

Reason for revert:
This was probably an infrastructure problem caused by the mac ninja/goma switch.

Original issue's description:
> Revert of [es6] don't throw if argument is non-object (O.freeze, O.seal, O.preventExtensions) (patchset #7 id:140001 of https://codereview.chromium.org/1011823003/)
>
> Reason for revert:
> [Sheriff] breaks mac gc stress:
> http://build.chromium.org/p/client.v8/builders/V8%20Mac%20GC%20Stress/builds/1029
>
> Original issue's description:
> > [es6] don't throw if argument is non-object (O.freeze, O.seal, O.preventExtensions)
> >
> > BUG=v8:3965, v8:3966
> > R=arv@chromium.org
> > LOG=N
> >
> > Committed: https://crrev.com/b09c048f693d280052ac63c7d6b3baf27b3bf271
> > Cr-Commit-Position: refs/heads/master@{#27985}
>
> TBR=arv@chromium.org,caitpotter88@gmail.com
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=v8:3965, v8:3966

TBR=arv@chromium.org,caitpotter88@gmail.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:3965, v8:3966

Review URL: https://codereview.chromium.org/1098243002

Cr-Commit-Position: refs/heads/master@{#27999}

Revert of Protect the emptiness of Array prototype elements with a PropertyCell. (patchset #7 id:120001 of https://codereview.chromium.org/1092043002/)

Reason for revert:
MAC GCSTRESS failure on new test.

Original issue's description:
> Protect the emptiness of Array prototype elements with a PropertyCell.
>
> Not just emptiness, but also a particular structure.
>
> BUG=v8:4044
> LOG=N

TBR=jkummerow@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4044

Review URL: https://codereview.chromium.org/1099203004

Cr-Commit-Position: refs/heads/master@{#27998}

Revert of Revert of [es6] implement Array.prototype.copyWithin() (patchset #1 id:1 of https://codereview.chromium.org/1084183004/)

Reason for revert:
Check if this CL fails independently of https://chromium.googlesource.com/v8/v8/+/580d66bcda66220d2f3062ac58daf925436df74c

Original issue's description:
> Revert of [es6] implement Array.prototype.copyWithin() (patchset #7 id:120001 of https://codereview.chromium.org/376623004/)
>
> Reason for revert:
> [Sheriff] This causes test failures on mac gc stress:
> http://build.chromium.org/p/client.v8/builders/V8%20Mac%20GC%20Stress/builds/1027
>
> Original issue's description:
> > [es6] implement Array.prototype.copyWithin()
> >
> > https://people.mozilla.org/~jorendorff/es6-draft.html#sec-array.prototype.copywithin
> >
> > BUG=v8:4039
> > R=adamk@chromium.org
> > LOG=N
>
> TBR=dslomov@chromium.org,rossberg@chromium.org,adamk@chromium.org,caitpotter88@gmail.com
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=v8:4039
>
> Committed: https://crrev.com/9283fc89710e59445bdc4479454fba97ab9ebdd7
> Cr-Commit-Position: refs/heads/master@{#27984}

TBR=dslomov@chromium.org,rossberg@chromium.org,adamk@chromium.org,caitpotter88@gmail.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4039

Review URL: https://codereview.chromium.org/1072193005

Cr-Commit-Position: refs/heads/master@{#27997}

R=hablich@chromium.org

Review URL: https://codereview.chromium.org/1105483002

Cr-Commit-Position: refs/heads/master@{#27996}

Instead, views have to check their array buffer for whether
it's neutered or not.

BUG=v8:3996
R=hpayer@chromium.org,dslomov@chromium.org,verwaest@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/1094863002

Cr-Commit-Position: refs/heads/master@{#27995}

BUG=

Review URL: https://codereview.chromium.org/1104463002

Cr-Commit-Position: refs/heads/master@{#27994}

Not just emptiness, but also a particular structure.

BUG=v8:4044
LOG=N

Review URL: https://codereview.chromium.org/1092043002

Cr-Commit-Position: refs/heads/master@{#27993}

TBR=svenpanne@chromium.org, titzer@chromium.org, bmeurer@chromium.org,
NOTRY=true
NOTREECHECKS=true

Review URL: https://codereview.chromium.org/1101653002

Cr-Commit-Position: refs/heads/master@{#27992}

Revert of [strong] checking of this & super in constructors (patchset #7 id:110001 of https://codereview.chromium.org/1024063002/)

Reason for revert:
[Sheriff] Breaks mac gc stress:
http://build.chromium.org/p/client.v8/builders/V8%20Mac%20GC%20Stress/builds/1024

Original issue's description:
> [strong] checking of this & super in constructors
>
> R=dslomov@chromium.org, marja@chromium.org
> BUG=v8:3956
> LOG=N
>
> Enforces for constructors that
> - the only use of 'super' is the super constructor call
> - the only use of 'this' is a property assignment
> - both of these must happen at the top-level of the body
> - 'this' may only be assigned after the 'super' call
> - 'return' may only be used after the last assignment to 'this'
>
> Not yet working for arrow functions (there might be deeper bugs with those).
>
> Committed: https://crrev.com/580d66bcda66220d2f3062ac58daf925436df74c
> Cr-Commit-Position: refs/heads/master@{#27977}

TBR=dslomov@chromium.org,marja@chromium.org,conradw@chromium.org,rossberg@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:3956

Review URL: https://codereview.chromium.org/1105453002

Cr-Commit-Position: refs/heads/master@{#27991}

Revert of [es6] don't throw if argument is non-object (O.freeze, O.seal, O.preventExtensions) (patchset #7 id:140001 of https://codereview.chromium.org/1011823003/)

Reason for revert:
[Sheriff] breaks mac gc stress:
http://build.chromium.org/p/client.v8/builders/V8%20Mac%20GC%20Stress/builds/1029

Original issue's description:
> [es6] don't throw if argument is non-object (O.freeze, O.seal, O.preventExtensions)
>
> BUG=v8:3965, v8:3966
> R=arv@chromium.org
> LOG=N
>
> Committed: https://crrev.com/b09c048f693d280052ac63c7d6b3baf27b3bf271
> Cr-Commit-Position: refs/heads/master@{#27985}

TBR=arv@chromium.org,caitpotter88@gmail.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:3965, v8:3966

Review URL: https://codereview.chromium.org/1103473003

Cr-Commit-Position: refs/heads/master@{#27990}

Also adjust the test runner to remove --always-opt for FAST_VARIANTS.

R=machenbach@chromium.org

Review URL: https://codereview.chromium.org/1056423004

Cr-Commit-Position: refs/heads/master@{#27989}

R=ulan@chromium.org
BUG=v8:4050
LOG=N

Review URL: https://codereview.chromium.org/1099103003

Cr-Commit-Position: refs/heads/master@{#27988}

This reverts commit bb346227 because it
adds a lot of overhead without significantly increasing our test
coverage. We need a different approach to deal with this.

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/1099813007

Cr-Commit-Position: refs/heads/master@{#27987}

Rolling v8/tools/clang to 442f528de2269272de9610e9c7186047ce4aaadb

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/1065783004

Cr-Commit-Position: refs/heads/master@{#27986}

BUG=v8:3965, v8:3966
R=arv@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1011823003

Cr-Commit-Position: refs/heads/master@{#27985}

Revert of [es6] implement Array.prototype.copyWithin() (patchset #7 id:120001 of https://codereview.chromium.org/376623004/)

Reason for revert:
[Sheriff] This causes test failures on mac gc stress:
http://build.chromium.org/p/client.v8/builders/V8%20Mac%20GC%20Stress/builds/1027

Original issue's description:
> [es6] implement Array.prototype.copyWithin()
>
> https://people.mozilla.org/~jorendorff/es6-draft.html#sec-array.prototype.copywithin
>
> BUG=v8:4039
> R=adamk@chromium.org
> LOG=N

TBR=dslomov@chromium.org,rossberg@chromium.org,adamk@chromium.org,caitpotter88@gmail.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4039

Review URL: https://codereview.chromium.org/1084183004

Cr-Commit-Position: refs/heads/master@{#27984}

https://people.mozilla.org/~jorendorff/es6-draft.html#sec-array.prototype.copywithin

BUG=v8:4039
R=adamk@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/376623004

Cr-Commit-Position: refs/heads/master@{#27983}

Revert of track global accesses to constant types (patchset #15 id:280001 of https://codereview.chromium.org/1062163005/)

Reason for revert:
[Sheriff] Speculative revert for maybe breaking layout tests, e.g.
http://build.chromium.org/p/client.v8/builders/V8-Blink%20Linux%2032/builds/2589

Will reland if it doesn't help.

Original issue's description:
> track global accesses to constant types
>
> BUG=

TBR=verwaest@chromium.org,dcarney@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/1094313003

Cr-Commit-Position: refs/heads/master@{#27982}

Revert of fix bad rebase in r27966 (patchset #1 id:1 of https://codereview.chromium.org/1083923005/)

Reason for revert:
Needed to revert https://chromium.googlesource.com/v8/v8/+/7bcc3d10835105fadc8ecf42a877dec479f0f80d

Original issue's description:
> fix bad rebase in r27966
>
> TBR=verwaest@chromium.org
>
> BUG=

TBR=verwaest@chromium.org,dcarney@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/1093043003

Cr-Commit-Position: refs/heads/master@{#27981}

BUG=v8:3018
R=dslomov@chromium.org, arv@chromium.org, rossberg@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1096363002

Cr-Commit-Position: refs/heads/master@{#27980}

Note: can't be landed until LoadProperty => LoadNamed is fixed.

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1101473004

Cr-Commit-Position: refs/heads/master@{#27979}

BUG=v8:2159
R=arv@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1099813005

Cr-Commit-Position: refs/heads/master@{#27978}

R=dslomov@chromium.org, marja@chromium.org
BUG=v8:3956
LOG=N

Enforces for constructors that
- the only use of 'super' is the super constructor call
- the only use of 'this' is a property assignment
- both of these must happen at the top-level of the body
- 'this' may only be assigned after the 'super' call
- 'return' may only be used after the last assignment to 'this'

Not yet working for arrow functions (there might be deeper bugs with those).

Review URL: https://codereview.chromium.org/1024063002

Cr-Commit-Position: refs/heads/master@{#27977}

This was a TODO for a while in crankshaft, now ready to address.

BUG=
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/1093413002

Cr-Commit-Position: refs/heads/master@{#27976}