[builtins] Migrate String.fromCharCode to TurboFan code stub.

[builtins] Migrate String.fromCharCode to TurboFan code stub.

When we moved the String.fromCharCode builtin to C++, we slightly
regressed the fast single character code argument case. Recovered some
of the performance by implementing the builtin using the TurboFan
CodeStubAssembler.

Drive-by-fix: Make sure the stack trace from the implicit ToNumber
conversion in String.fromCharCode includes the builtin by adding a
regression test for that.

R=yangguo@chromium.org
BUG=chromium:609831, chromium:613947, v8:5049
Committed: https://crrev.com/7554360f28adebd086761c3636c004a1013ebbb5
Cr-Commit-Position: refs/heads/master@{#36611}

[Benedikt Meurer, 2016-05-31 10:58:05]

Description was changed from

==========
[builtins] Migrate String.fromCharCode to TurboFan code stub.

When we moved the String.fromCharCode builtin to C++, we slightly
regressed the fast single character code argument case. Recovered some
of the performance by implementing the builtin using the TurboFan
CodeStubAssembler.

Drive-by-fix: Make sure the stack trace from the implicit ToNumber
conversion in String.fromCharCode includes the builtin by adding a
regression test for that.

R=yangguo@chromium.org
BUG=chromium:613947
==========

to

==========
[builtins] Migrate String.fromCharCode to TurboFan code stub.

When we moved the String.fromCharCode builtin to C++, we slightly
regressed the fast single character code argument case. Recovered some
of the performance by implementing the builtin using the TurboFan
CodeStubAssembler.

Drive-by-fix: Make sure the stack trace from the implicit ToNumber
conversion in String.fromCharCode includes the builtin by adding a
regression test for that.

R=yangguo@chromium.org
BUG=chromium:609831,chromium:613947,v8:5049
==========

[Benedikt Meurer, 2016-05-31 10:58:24]

Hey Yang,

Some followup performance work for String.fromCharCode.
Please take a look.

Thanks,
Benedikt

[Yang, 2016-05-31 11:34:12]

On 2016/05/31 10:58:24, Benedikt Meurer wrote:
> Hey Yang,
> 
> Some followup performance work for String.fromCharCode.
> Please take a look.
> 
> Thanks,
> Benedikt

LGTM.

[Benedikt Meurer, 2016-05-31 11:35:44]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2016-05-31 11:35:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2021143003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2021143003/1

[commit-bot: I haz the power, 2016-05-31 11:37:31]

Description was changed from

==========
[builtins] Migrate String.fromCharCode to TurboFan code stub.

When we moved the String.fromCharCode builtin to C++, we slightly
regressed the fast single character code argument case. Recovered some
of the performance by implementing the builtin using the TurboFan
CodeStubAssembler.

Drive-by-fix: Make sure the stack trace from the implicit ToNumber
conversion in String.fromCharCode includes the builtin by adding a
regression test for that.

R=yangguo@chromium.org
BUG=chromium:609831,chromium:613947,v8:5049
==========

to

==========
[builtins] Migrate String.fromCharCode to TurboFan code stub.

When we moved the String.fromCharCode builtin to C++, we slightly
regressed the fast single character code argument case. Recovered some
of the performance by implementing the builtin using the TurboFan
CodeStubAssembler.

Drive-by-fix: Make sure the stack trace from the implicit ToNumber
conversion in String.fromCharCode includes the builtin by adding a
regression test for that.

R=yangguo@chromium.org
BUG=chromium:609831,chromium:613947,v8:5049
==========

[commit-bot: I haz the power, 2016-05-31 11:37:32]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-05-31 11:39:15]

Description was changed from

==========
[builtins] Migrate String.fromCharCode to TurboFan code stub.

When we moved the String.fromCharCode builtin to C++, we slightly
regressed the fast single character code argument case. Recovered some
of the performance by implementing the builtin using the TurboFan
CodeStubAssembler.

Drive-by-fix: Make sure the stack trace from the implicit ToNumber
conversion in String.fromCharCode includes the builtin by adding a
regression test for that.

R=yangguo@chromium.org
BUG=chromium:609831,chromium:613947,v8:5049
==========

to

==========
[builtins] Migrate String.fromCharCode to TurboFan code stub.

When we moved the String.fromCharCode builtin to C++, we slightly
regressed the fast single character code argument case. Recovered some
of the performance by implementing the builtin using the TurboFan
CodeStubAssembler.

Drive-by-fix: Make sure the stack trace from the implicit ToNumber
conversion in String.fromCharCode includes the builtin by adding a
regression test for that.

R=yangguo@chromium.org
BUG=chromium:609831,chromium:613947,v8:5049

Committed: https://crrev.com/7554360f28adebd086761c3636c004a1013ebbb5
Cr-Commit-Position: refs/heads/master@{#36611}
==========

[commit-bot: I haz the power, 2016-05-31 11:39:16]

Patchset 1 (id:??) landed as
https://crrev.com/7554360f28adebd086761c3636c004a1013ebbb5
Cr-Commit-Position: refs/heads/master@{#36611}