[turbofan] Use FastNewClosureStub if possible.

[turbofan] Use FastNewClosureStub if possible.

This introduces a JSCreateClosure operator which can be lowered by the
typed pipeline to the aforementioned stub. It also allows for further
optimizations of closure creation.

R=titzer@chromium.org

Committed: https://crrev.com/a38f9dddd19a90039f0914b88ab37a3837a3c2f6
Cr-Commit-Position: refs/heads/master@{#28058}

[titzer, 2015-04-27 08:38:48]

https://codereview.chromium.org/1105513002/diff/40001/src/compiler/js-operator.h
File src/compiler/js-operator.h (right):

https://codereview.chromium.org/1105513002/diff/40001/src/compiler/js-operato...
src/compiler/js-operator.h:211: class CreateClosureParameters final {
Make me a struct?

https://codereview.chromium.org/1105513002/diff/40001/src/compiler/typer.cc
File src/compiler/typer.cc (right):

https://codereview.chromium.org/1105513002/diff/40001/src/compiler/typer.cc#n...
src/compiler/typer.cc:1315: return Bounds(Type::None(), Type::OtherObject());
Now that's precise.

[titzer, 2015-04-27 08:41:37]

lgtm

[Michael Starzinger, 2015-04-27 09:04:52]

The CQ bit was checked by mstarzinger@chromium.org

[Michael Starzinger, 2015-04-27 09:04:53]

The patchset sent to the CQ was uploaded after l-g-t-m from titzer@chromium.org
Link to the patchset: https://codereview.chromium.org/1105513002/#ps60001
(title: "Rebased.")

[commit-bot: I haz the power, 2015-04-27 09:04:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1105513002/60001

[commit-bot: I haz the power, 2015-04-27 09:08:25]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-04-27 09:08:40]

Patchset 4 (id:??) landed as
https://crrev.com/a38f9dddd19a90039f0914b88ab37a3837a3c2f6
Cr-Commit-Position: refs/heads/master@{#28058}