Simplify v8/Isolate teardown.

Simplify v8/Isolate teardown.

This implies that one better has a v8::V8::Initialize when v8::V8::Dispose is used.


BUG=359977
LOG=y
R=jochen@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=20876

[jochen (gone - plz use gerrit), 2014-04-17 13:24:56]

lgtm

https://codereview.chromium.org/238353015/diff/1/src/arm/assembler-arm.cc
File src/arm/assembler-arm.cc (right):

https://codereview.chromium.org/238353015/diff/1/src/arm/assembler-arm.cc#new...
src/arm/assembler-arm.cc:107: (supported_ & standard_features) ==
standard_features);
unrelated?

https://codereview.chromium.org/238353015/diff/1/test/cctest/test-api.cc
File test/cctest/test-api.cc (right):

https://codereview.chromium.org/238353015/diff/1/test/cctest/test-api.cc#newc...
test/cctest/test-api.cc:22316: i::FlagList::EnforceFlagImplications();
unrelated?

[Sven Panne, 2014-04-22 07:28:36]

https://codereview.chromium.org/238353015/diff/1/src/arm/assembler-arm.cc
File src/arm/assembler-arm.cc (right):

https://codereview.chromium.org/238353015/diff/1/src/arm/assembler-arm.cc#new...
src/arm/assembler-arm.cc:107: (supported_ & standard_features) ==
standard_features);
On 2014/04/17 13:24:57, jochen wrote:
> unrelated?

Alas, no: ARM has to be treated specially, which is quite unfortunate, but this
cleanup is better done in a separate CL. Furthermore, the ASSERT is more
correct: It makes sure that repeated Probe calls don't remove features.

https://codereview.chromium.org/238353015/diff/1/test/cctest/test-api.cc
File test/cctest/test-api.cc (right):

https://codereview.chromium.org/238353015/diff/1/test/cctest/test-api.cc#newc...
test/cctest/test-api.cc:22316: i::FlagList::EnforceFlagImplications();
On 2014/04/17 13:24:57, jochen wrote:
> unrelated?

Nope, this is crucial: Promises need weak maps, but the implications have
already been processed at this point.

We should really, really clean up our flag handling and avoid setting/reading
global variables directly.

[Sven Panne, 2014-04-22 09:25:13]

Committed patchset #2 manually as r20876 (presubmit successful).