[builtins] introduce AsyncBuiltinsAssembler for ES2016 features and beyond

[builtins] introduce AsyncBuiltinsAssembler for ES2016 features and beyond

First step in splitting apart https://codereview.chromium.org/2622833002/ to
land piece by piece.

Porting src/js/async-await.js to TF builtins using this boilerplate is
now very straightforward.

BUG=v8:4483, v8:5855
R=jgruber@chromium.org, gsathya@chromium.org

Review-Url: https://codereview.chromium.org/2635353002
Cr-Commit-Position: refs/heads/master@{#42466}
Committed: https://chromium.googlesource.com/v8/v8/+/4173fda417a38765d4fd72454959bc953b0062c8

[caitp, 2017-01-17 22:20:26]

The CQ bit was checked by caitp@igalia.com to run a CQ dry run

[commit-bot: I haz the power, 2017-01-17 22:20:36]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[caitp, 2017-01-17 22:25:41]

I believe this is all the boilerplate needed for implementing async-await.js in
TF.

AsyncBuiltinsAssembler::Await() is difficult to test by itself (Due to requiring
changing native_context()), so this patch does not contain test coverage --- but
once async-await.js is ported to TF on top of it (if this is the approach we go
with), it should add some tests to ensure promise hooks and behaviour are all as
expected.

[jgruber, 2017-01-18 11:59:32]

lgtm

[caitp, 2017-01-18 15:12:15]

The CQ bit was checked by caitp@igalia.com

[commit-bot: I haz the power, 2017-01-18 15:12:21]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-01-18 15:41:03]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1484752335746400,
"parent_rev": "d62914f6e9819a9def5068f8afea2ca8c01f52d3", "commit_rev":
"4173fda417a38765d4fd72454959bc953b0062c8"}

[commit-bot: I haz the power, 2017-01-18 15:41:07]

Description was changed from

==========
[builtins] introduce AsyncBuiltinsAssembler for ES2016 features and beyond

First step in splitting apart https://codereview.chromium.org/2622833002/ to
land piece by piece.

Porting src/js/async-await.js to TF builtins using this boilerplate is
now very straightforward.

BUG=v8:4483, v8:5855
R=jgruber@chromium.org, gsathya@chromium.org
==========

to

==========
[builtins] introduce AsyncBuiltinsAssembler for ES2016 features and beyond

First step in splitting apart https://codereview.chromium.org/2622833002/ to
land piece by piece.

Porting src/js/async-await.js to TF builtins using this boilerplate is
now very straightforward.

BUG=v8:4483, v8:5855
R=jgruber@chromium.org, gsathya@chromium.org

Review-Url: https://codereview.chromium.org/2635353002
Cr-Commit-Position: refs/heads/master@{#42466}
Committed:
https://chromium.googlesource.com/v8/v8/+/4173fda417a38765d4fd72454959bc953b0...
==========

[commit-bot: I haz the power, 2017-01-18 15:41:07]

Committed patchset #3 (id:40001) as
https://chromium.googlesource.com/v8/v8/+/4173fda417a38765d4fd72454959bc953b0...

[jgruber, 2017-01-20 08:17:19]

https://codereview.chromium.org/2635353002/diff/40001/src/builtins/builtins-a...
File src/builtins/builtins-async.cc (right):

https://codereview.chromium.org/2635353002/diff/40001/src/builtins/builtins-a...
src/builtins/builtins-async.cc:64: CallRuntime(Runtime::kSetProperty, on_reject,
key, TrueConstant(),
Just noticed that context is missing here as the second parameter (below as
well). Fixing in https://codereview.chromium.org/2643023002/.