Port d61a5c37

Original commit message:

    As a first step I uncommit the memory on the main thread. Also
    to measure impact and stability of that optimization. In a
    follow-up CL, the uncommitting should be moved on the concurrent thread.

R=jochen@chromium.org, hpayer@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2245703002
Cr-Commit-Position: refs/heads/master@{#38654}

Slots in ConsString/SlicedString can point to an evacutaion candidate.
The MakeExternal function makes in-place conversion to external string.
After the conversion we can have a recorded slot containing an external
pointer. As long as the external pointer is aligned, this is not a
problem. We clear the recorded slots to fix verify-heap checks.

BUG=chromium:631969
LOG=NO

Finalizing CL: https://codereview.chromium.org/2199863002/

Review-Url: https://codereview.chromium.org/2242183003
Cr-Commit-Position: refs/heads/master@{#38653}

BUG=

Review-Url: https://codereview.chromium.org/2241503002
Cr-Commit-Position: refs/heads/master@{#38652}

Allows us to create a corresponding TurboFan node, so TF can
optimize it.

BUG=v8:4280
LOG=n

Review-Url: https://codereview.chromium.org/2248633002
Cr-Commit-Position: refs/heads/master@{#38651}

This moves language-mode initialization for MODULE_SCOPE from Scope::SetDefaults to the single constructor that needs to do it. The CL additionally makes it more obvious that scope-info-backed scopes always initialize language-mode unless WITH_SCOPE.

BUG=

Review-Url: https://codereview.chromium.org/2251683002
Cr-Commit-Position: refs/heads/master@{#38650}

[turbofan] Instead of using properties, use a whitelist for store-store elimination. Make --turbo imply --turbo-store-elimination, so it is tested by ClusterFuzz.

This should fix bug v8:5280.

BUG=v8:5280

Review-Url: https://codereview.chromium.org/2236443006
Cr-Commit-Position: refs/heads/master@{#38649}

This stages the --ignition-preserve-bytecode flag which preserves the
bytecode even when switching to baseline code. It is now implied by the
combined --ignition-staging flag.

R=rmcilroy@chromium.org

Review-Url: https://codereview.chromium.org/2244303003
Cr-Commit-Position: refs/heads/master@{#38648}

BUG=v8:5291
R=titzer@chromium.org

Review-Url: https://codereview.chromium.org/2241203004
Cr-Commit-Position: refs/heads/master@{#38647}

BUG=v8:5209

Review-Url: https://codereview.chromium.org/2247073003
Cr-Commit-Position: refs/heads/master@{#38646}

Simple stack traces are captured through Isolate::CaptureSimpleStackTrace.
Captured frames are stored in a FixedArray, which in turn is stored as a
property (using a private symbol) on the error object itself. Actual formatting
of the textual stack trace is done lazily when the user reads the stack
property of the error object.

This would involve many conversions back and forth between index-encoded raw
data (receiver, function, offset and code), JS CallSite objects, and C++
CallSite objects.

This commit refactors the C++ CallSite class into a Struct class called
StackTraceFrame, which is the new single point of truth frame information.
Isolate::CaptureSimpleStackTrace stores an array of StackTraceFrames, and JS
CallSite objects (now created only when the user specifies custom stack trace
formatting through Error.prepareStackTrace) internally only store a reference
to a StackTraceFrame.

BUG=

Review-Url: https://codereview.chromium.org/2230953002
Cr-Commit-Position: refs/heads/master@{#38645}

A test exercising the public APIs for wasm serialization and
simulates the serialization scenario - serialize in one isolate, deserialize
in another.

BUG=v8:5072

Review-Url: https://codereview.chromium.org/2249973002
Cr-Commit-Position: refs/heads/master@{#38644}

Follow-up cleanup to https://codereview.chromium.org/2231813003

BUG=

Review-Url: https://codereview.chromium.org/2237873002
Cr-Commit-Position: refs/heads/master@{#38643}

Rolling v8/build to f5aadfbec4267ecafa3200c571131c84d1ced4be

Rolling v8/third_party/WebKit/Source/platform/inspector_protocol to e17560795294ff0c23bdae7665ec71c95a75561e

Rolling v8/tools/clang to ad9e1e262ff737d779bb2e5b49e3987547f05694

Rolling v8/tools/mb to e89c543a2ab08d70b876130ac83c04a92daffeaf

TBR=machenbach@chromium.org,vogelheim@chromium.org,hablich@chromium.org

Review-Url: https://codereview.chromium.org/2249993002
Cr-Commit-Position: refs/heads/master@{#38642}

R=verwaest@chromium.org

Review-Url: https://codereview.chromium.org/2248813002
Cr-Commit-Position: refs/heads/master@{#38641}

R=joransiu@ca.ibm.com, michael_dawson@ca.ibm.com, mbrandy@us.ibm.com, bjaideep@ca.ibm.com
BUG=

Review-Url: https://codereview.chromium.org/2244373002
Cr-Commit-Position: refs/heads/master@{#38640}

Review-Url: https://codereview.chromium.org/2246963002
Cr-Commit-Position: refs/heads/master@{#38639}

The structure of this code changed in https://codereview.chromium.org/2201193004,
but the structural changes were not essential to that CL's purpose (which was
to use Variable::binding_needs_init() consistently to decide whether to
hole-check). Now the code should appear as it did before that change, but with
the addition of binding_needs_init() checks.

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

Review-Url: https://codereview.chromium.org/2237933002
Cr-Commit-Position: refs/heads/master@{#38638}

Removes dependence on InnerArrayIndexOf/InnerArrayLastIndexOf and
reduces type polution caused by sharing these functions between standard
and typed arrays.

BUG=

Review-Url: https://codereview.chromium.org/2243523002
Cr-Commit-Position: refs/heads/master@{#38637}

This includes UTF-8 strings and two-byte strings, both length-delimited
(in bytes, not characters). Two-byte strings are written/read in host byte
order.

BUG=chromium:148757

Review-Url: https://codereview.chromium.org/2245753002
Cr-Commit-Position: refs/heads/master@{#38636}

Add an extra paramter to disable scale on BaseWithIndexAndDisplacementMatcher.

R=bmeurer@chromium.org, epertoso@chromium.org, jarin@chromium.org, mstarzinger@chromium.org, mtrofin@chromium.org, titzer@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2239813002
Cr-Commit-Position: refs/heads/master@{#38635}

Adds TestResultScope and uses it to directly jump/fall through to the
correct branch in expressions used as branch conditions.
Should enable nicer TurboFan-graphs for easier control-flow
transformations in the future.

BUG=v8:4280
LOG=n

Review-Url: https://codereview.chromium.org/2242463002
Cr-Commit-Position: refs/heads/master@{#38634}

Removes Variable::is_possibly_eval() and instead stores whether
a call is possibly eval in the Call node's bitfield.

Also removes HandleDereferenceMode since it's no longer used.

BUG=v8:5203

Review-Url: https://codereview.chromium.org/2242583003
Cr-Commit-Position: refs/heads/master@{#38633}

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2193063003
Cr-Commit-Position: refs/heads/master@{#38632}

Rolling v8/third_party/WebKit/Source/platform/inspector_protocol to ac24d974a70c8611d2837e183d6cf99f39fb0410

TBR=machenbach@chromium.org,vogelheim@chromium.org,hablich@chromium.org

Review-Url: https://codereview.chromium.org/2244173002
Cr-Commit-Position: refs/heads/master@{#38631}

This includes unsigned integers (encoded as base-128 varints), signed integers
(ZigZag-encoded, then varint-encoded) and doubles (written in host byte order).

BUG=chromium:148757

Review-Url: https://codereview.chromium.org/2232323004
Cr-Commit-Position: refs/heads/master@{#38630}

Rolling v8/build to 4155375bddb65fe3d2dbc42ab0d64c4d72527165

Rolling v8/third_party/WebKit/Source/platform/inspector_protocol to 9d440c96636c5a41ce3e40f1924fe41dd2694f51

TBR=machenbach@chromium.org,vogelheim@chromium.org,hablich@chromium.org

Review-Url: https://codereview.chromium.org/2244113002
Cr-Commit-Position: refs/heads/master@{#38629}

Rolling v8/build to 45574dce74fca42e485fbc5cd78bd24bcfeb905f

Rolling v8/buildtools to adb8bf4e8fc92aa1717bf151b862d58e6f27c4f2

Rolling v8/tools/clang to 6d377a47e9c668c7550d17a7d4e6ba9f5931703a

Rolling v8/tools/mb to c78da3f5bccc979b35907c4cbf937aa5187e41fa

TBR=machenbach@chromium.org,vogelheim@chromium.org,hablich@chromium.org

Review-Url: https://codereview.chromium.org/2240213004
Cr-Commit-Position: refs/heads/master@{#38628}

No longer include the "async" keyword, or an async arrow function's single
identifier parameter as part of its inferred name.

BUG=v8:5281, v8:4483
R=adamk@chromium.org, littledan@chromium.org, marja@chromium.org

Review-Url: https://codereview.chromium.org/2235423003
Cr-Commit-Position: refs/heads/master@{#38627}

Throw 'Range Error: invalid string length' when the result of
case mapping is longer than the max string length (kMaxLength in
objects.h = 1 << 28 - 16).

This is for case mapping with ICU.

A new test (case-mapping-slow.js) is added with PASS,SLOW. It's
configured to skip unless arch=x64 and mode=release and not on
simulator.

This is a reattempt to land
 https://codereview.chromium.org/2236593002 that was reverted.

BUG=v8:5271
TEST=intl/general/case-mapping-slow.js with --icu_case_mapping

Review-Url: https://codereview.chromium.org/2236963003
Cr-Commit-Position: refs/heads/master@{#38626}

BUG=chromium:148757

Review-Url: https://codereview.chromium.org/2232243003
Cr-Commit-Position: refs/heads/master@{#38625}

The hand-written KeyedLoadIC_Megamorphic stub didn't care about JSArray
lengths, which made it lenient towards said lengths being wrong, but it
will soon fix that bug and thereby become more strict.

LiveEdit: factory->NewJSArray(capacity) doesn't set a length, so set it
manually.
RegExp: to avoid having to take care of array length updating in the
RegExpExecStub, just use a JSObject instead.

Review-Url: https://codereview.chromium.org/2244673002
Cr-Commit-Position: refs/heads/master@{#38624}

Revert of [interpreter] Inline ForInFilter stub. (patchset #1 id:1 of https://codereview.chromium.org/2220343002/ )

Reason for revert:
Speculative revert to possible performance regressions.

BUG=chromium:635826,chromium:635930

Original issue's description:
> [interpreter] Inline ForInFilter stub.
>
> BUG=v8:4280
> LOG=N
>
> Committed: https://crrev.com/2bf0b8c8ed5d0c93982c8c227e93622aceecea16
> Cr-Commit-Position: refs/heads/master@{#38420}

TBR=oth@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=v8:4280

Review-Url: https://codereview.chromium.org/2238283002
Cr-Commit-Position: refs/heads/master@{#38623}

    Instead of loading 64 bits and shifting:

      ldr x0, [x1, #offset]
      asr x0, x0, #32

    directly load the interesting 32 bits and sign-extend:

      ldrsw x0, [x1, #offset+4]

BUG=

Review-Url: https://codereview.chromium.org/2243843002
Cr-Commit-Position: refs/heads/master@{#38622}

R=jgruber@chromium.org, mstarzinger@chromium.org
BUG=v8:5265

Review-Url: https://codereview.chromium.org/2246483002
Cr-Commit-Position: refs/heads/master@{#38621}

This adds a shortcut to the compilation pipeline that makes sure we are
not regenerating bytecode when it has been preserved from a previous
request. This can happen when code flushing removes baseline code,
thereby clearing the entry trampoline but leaving bytecode intact.

R=yangguo@chromium.org
BUG=v8:5265

Review-Url: https://codereview.chromium.org/2241783002
Cr-Commit-Position: refs/heads/master@{#38620}

kudos to marja@ for finding this

BUG=v8:5209

Review-Url: https://codereview.chromium.org/2243833002
Cr-Commit-Position: refs/heads/master@{#38619}

Also, re-enables the use of the type feedback in BytecodeGraphBuilder.

BUG=v8:5273
LOG=N

Review-Url: https://codereview.chromium.org/2235133003
Cr-Commit-Position: refs/heads/master@{#38618}

This removes some compiler internals as well as some JavaScript specific
helper from the CodeAssembler, by either hiding or moving the support
into the CodeStubAssembler.

R=bmeurer@chromium.org

Review-Url: https://codereview.chromium.org/2246463002
Cr-Commit-Position: refs/heads/master@{#38617}

This should be faster and should give the same result.

BUG=v8:5203

Review-Url: https://codereview.chromium.org/2243783002
Cr-Commit-Position: refs/heads/master@{#38616}

Properly deoptimize if the left hand side of a CheckedInt32Mod is
negative and the result of the operation is zero.

R=jarin@chromium.org
BUG=v8:5286

Review-Url: https://codereview.chromium.org/2243803002
Cr-Commit-Position: refs/heads/master@{#38615}