This relands parts of
https://codereview.chromium.org/843913009

It prepares for using this script outside of v8, e.g. in a
chromium hook.

The script is intended to run as a hook and will create
version_gen.cc if the content has changed.

Changes to gyp and gn files can land as a follow up, once
calling the hook on the chromium side has landed.

BUG=chromium:446166
LOG=n

Review URL: https://codereview.chromium.org/830093003

Cr-Commit-Position: refs/heads/master@{#26144}

Revert of Temporarily restore make dependencies (patchset #1 id:1 of https://codereview.chromium.org/733203008/)

Reason for revert:
make dependencies is stale now, and everybody should have switched over

Original issue's description:
> Temporarily restore make dependencies
>
> We will remove dependencies in about a week again.
>
> BUG=none
> R=machenbach@chromium.org
> LOG=y

TBR=machenbach@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=none

Review URL: https://codereview.chromium.org/791813007

Cr-Commit-Position: refs/heads/master@{#26134}

Contribution of PowerPC port (continuation of 422063005). The inital patch
covers the core changes to the common files.  Subsequent patches will cover
changes to common files to support AIX and to update the ppc directories so
they are current with the changes in the rest of the project.

This is based off of the GitHub repository
https://github.com/andrewlow/v8ppc

BUG=
R=svenpanne@chromium.org, danno@chromium.org, sevnpanne@chromium.org

Review URL: https://codereview.chromium.org/817143002

Cr-Commit-Position: refs/heads/master@{#26091}

Also make sure that x86_64 is mapped to x64 as target arch

R=machenbach@chromium.org
LOG=n
BUG=none

Review URL: https://codereview.chromium.org/846363002

Cr-Commit-Position: refs/heads/master@{#26052}

R=vogelheim@chromium.org

Review URL: https://codereview.chromium.org/845973003

Cr-Commit-Position: refs/heads/master@{#26029}

All builders that used level 1 should meanwhile define
v8_enable_slow_dchecks, and so they can use level 2 without losing
coverage. Level 2, however, is considerably faster, so we want to use it
on those builders as well. The make optdebug setting is not affected by
this change.

BUG=none
R=machenbach@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/847753002

Cr-Commit-Position: refs/heads/master@{#26019}

The default for the various debug modes doesn't change.

In a follow-up, OptDebug1 and OptDebug2 will be merged

R=machenbach@chromium.org
LOG=y
BUG=none

Review URL: https://codereview.chromium.org/846653002

Cr-Commit-Position: refs/heads/master@{#26015}

Instead, just use DCHECKs. The builders that want them in release mode
should already be useding dcheck_always_on anyways

BUG=none
R=machenbach@chromium.org
LOG=y

Review URL: https://codereview.chromium.org/841083002

Cr-Commit-Position: refs/heads/master@{#26001}

The logic was supposed to trigger a rebuild if the CXX variable is
changed. However, it failed to track the other compiler related
variables, and, what is worse, conflicted with the clang=1 gyp setting
by forcing CXX to g++

The new logic just relies on tracking GYP defines, and checks whether
the CXX binary - if set - has a target different from the host
architecture.

BUG=none
R=jkummerow@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/807143003

Cr-Commit-Position: refs/heads/master@{#25973}

Review URL: https://codereview.chromium.org/791723004

Cr-Commit-Position: refs/heads/master@{#25741}

Revert of Use same blob format for internal and external snapshots. (patchset #2 id:20001 of https://codereview.chromium.org/787033002/)

Reason for revert:
[sheriff] breaks http://build.chromium.org/p/client.v8/builders/V8-Blink%20Linux%2064%20%28dbg%29/builds/1293

Original issue's description:
> Use same blob format for internal and external snapshots.
>
> R=vogelheim@chromium.org

TBR=vogelheim@chromium.org,yangguo@chromium.org
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/792563002

Cr-Commit-Position: refs/heads/master@{#25729}

R=vogelheim@chromium.org

Review URL: https://codereview.chromium.org/787033002

Cr-Commit-Position: refs/heads/master@{#25727}

We will remove dependencies in about a week again.

BUG=none
R=machenbach@chromium.org
LOG=y

Review URL: https://codereview.chromium.org/733203008

Cr-Commit-Position: refs/heads/master@{#25719}

Also remove the now disfunctinal 'builddeps' and 'dependencies' targets

BUG=none
R=machenbach@chromium.org,jkummerow@chromium.org
LOG=y

Review URL: https://codereview.chromium.org/788613002

Cr-Commit-Position: refs/heads/master@{#25710}

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/722613002

Cr-Commit-Position: refs/heads/master@{#25290}
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25290 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/694533003

Cr-Commit-Position: refs/heads/master@{#25219}
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25219 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

The turbocheck target is similar to quickcheck, but runs only the
turbofan variant.

R=machenbach@chromium.org

Review URL: https://codereview.chromium.org/697573002

Cr-Commit-Position: refs/heads/master@{#25026}
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25026 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=
R=ishell@chromium.org, jkummerow@chromium.org

Review URL: https://codereview.chromium.org/631763003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24419 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

As per discussion on the V8 team, this is the place we want them to live,
not following the Chrome Style Guide for this.

BUG=v8:3489
LOG=y
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/615393002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24350 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/594823002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24148 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Dependencies were updated in Chromium, see
https://codereview.chromium.org/425333002/ for details.

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/451993002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22984 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Because Benedikt said so.

BUG=none
LOG=y
R=bmeurer@chromium.org, machenbach@chromium.org

Review URL: https://codereview.chromium.org/434423002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22806 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Fix r22531, I dropped a necessary pair of parens.

BUG=
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/410003003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22565 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

r22509 fixed arm and mips (big-endian) cross-compilation builds.

It did not fix mipsel, mips64el, or arm64 builds, since the
toolchain prefix did not match the v8_target_arch.

For mips, the toolchain is typically named mips-linux-gnu-g++,
but it can compile for mipsel or mips64el via flags. (There can
also be mipsel-linux-gnu-g++ toolchains, and this patch will
work for mipsel build in that case).

For arm64, the toolchains seem to be named aarch64-linux-gnu-g++.

BUG=
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/408133002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22531 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=none
TBR=machenbach@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/412503002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22528 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=v8:3452
R=svenpanne@chromium.org
LOG=y

Review URL: https://codereview.chromium.org/411493002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22523 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/405113002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22509 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Summary:

- Changes in common code are mainly boilerplate changes,
gyp and test status files updates.

- On mips64 simulator all tests pass from all test units.

- Current issues: mjsunit JS debugger tests fail randomly on HW in release mode.
Corresponding tests are skipped on HW.

- Skipped tests on mips64: test-heap/ReleaseOverReservedPages, mjsunit/debug-*

TEST=
BUG=
R=danno@chromium.org, plind44@gmail.com, ulan@chromium.org

Review URL: https://codereview.chromium.org/371923006

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22297 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

In contrast to "dependencies", this only pulls in dependencies required
for building. The dependencies make target will also pull in development
tools and requires depot_tools to be installed and in the path.

BUG=v8:3418
LOG=y
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/363703002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22130 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Building d8 with msan requires instrumented libc++. Currently the
advised way to do this is from a chromium checkout with d8 as target.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/361963003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22124 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Currently works only in combination with i18nsupport=off.

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/367623002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22109 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Also add hooks to download clang-format binaries.

BUG=none
R=machenbach@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/334403005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22036 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

I don't know if there are any v8 bots with that configuration, but it seems
like a good idea to have v8 be consistent with chromium and nacl here, so that
this works fine if such a bot is ever set up.

This is similar to https://codereview.chromium.org/342493002/ , but with a
detect_v8_host_arch.py script that handles the additional machine types that
standalone.gypi used to handle.

Originally reviewed at https://codereview.chromium.org/346643002/

BUG=368384
LOG=Y
R=jochen@chromium.org

Review URL: https://codereview.chromium.org/349333006

Patch from Nico Weber <thakis@chromium.org>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21956 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/18014003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21955 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Simplify the compile time feature detection on Arm:
 - Define CAN_USE_XXX definitions unconditionally for all target/host
   toolchain combinations
 - Rename arm_test / ARM_TEST to arm_test_noprob / ARM_TEST_NO_FEATURE_PROBE
 - Don't set ARM_TEST_NO_FEATURE_PROBE implicitly on the simulator to make
   make simulator / native more consistent
 - Unify CpuFeatures::PrintTarget for simulator and native builds
 - Remove unecessary CAN_USE_VFP_INSTRUCTIONS definition for android (this is
   the default for arm_fpu=default)
 - Add a CpuFeatures::Probe() before calling CpuFeatures::PrintFeatures() in PrintHelp
    to ensure we have probed features before printing them.

BUG=384474
LOG=N
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/340373002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21935 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

In order to be able to use it one should pass verifypredictable=on to the make tool or specify v8_enable_verify_predictable=1 in GYP_DEFINES.

R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/325553002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21892 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

TBR=machenbach@chromium.org
LOG=n
BUG=none

Review URL: https://codereview.chromium.org/307403004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21656 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=none
R=machenbach@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/309933005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21639 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Currently, this adds checkdeps, in the future, this will be the place
where clang-format and gn lives.

BUG=none
R=machenbach@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/308353002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21636 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Support x87-only platform (ia32 without SSE)

R=danno@chromium.org

Review URL: https://codereview.chromium.org/293743005

Patch from Weiliang Lin <weiliang.lin@intel.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21469 ce2b1a6d-e550-0410-aec6-3dcde31c8c00