[turbofan] Implement sharing of context-independent code.

[turbofan] Implement sharing of context-independent code.

This allows context-independent code generated by TurboFan to be cached
in the optimized code map and reused across native contexts. Note that
currently this cache is still flushed at GC time.

R=bmeurer@chromium.org,mvstanton@chromium.org
TEST=cctest/test-compiler/OptimizedCodeSharing

Committed: https://crrev.com/317cb6538c5dcee14dea432fecc9cad5c9d1f605
Cr-Commit-Position: refs/heads/master@{#29313}

[Michael Starzinger, 2015-06-25 13:12:43]

mstarzinger@chromium.org changed reviewers:
+ bmeurer@chromium.org, mvstanton@chromium.org

[Michael Starzinger, 2015-06-25 13:12:44]

Michael: PTAL especially at the FastNewClosureStub port.
Benedikt: PTAL at everything else.

[Benedikt Meurer, 2015-06-26 06:34:53]

LGTM with comment. Thanks!

https://codereview.chromium.org/1208013002/diff/80001/src/code-stubs-hydrogen.cc
File src/code-stubs-hydrogen.cc (right):

https://codereview.chromium.org/1208013002/diff/80001/src/code-stubs-hydrogen...
src/code-stubs-hydrogen.cc:1794: HValue* literals =
Add<HConstant>(factory->empty_fixed_array());
Add a TODO here to share the literals for the context as well at some point.

[mvstanton, 2015-06-26 06:38:37]

Also LGTM, nice :).

[Michael Starzinger, 2015-06-26 08:30:25]

https://codereview.chromium.org/1208013002/diff/80001/src/code-stubs-hydrogen.cc
File src/code-stubs-hydrogen.cc (right):

https://codereview.chromium.org/1208013002/diff/80001/src/code-stubs-hydrogen...
src/code-stubs-hydrogen.cc:1794: HValue* literals =
Add<HConstant>(factory->empty_fixed_array());
On 2015/06/26 06:34:53, Benedikt Meurer wrote:
> Add a TODO here to share the literals for the context as well at some point.

Done. As discussed offline, I added it to the runtime version, because the stub
is only used if there are no literals in the first place.

[Michael Starzinger, 2015-06-26 08:46:10]

The CQ bit was checked by mstarzinger@chromium.org

[Michael Starzinger, 2015-06-26 08:46:10]

The patchset sent to the CQ was uploaded after l-g-t-m from
bmeurer@chromium.org, mvstanton@chromium.org
Link to the patchset: https://codereview.chromium.org/1208013002/#ps120001
(title: "Disable test for GC stress.")

[commit-bot: I haz the power, 2015-06-26 08:46:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1208013002/120001

[commit-bot: I haz the power, 2015-06-26 09:07:37]

Committed patchset #7 (id:120001)

[commit-bot: I haz the power, 2015-06-26 09:07:55]

Patchset 7 (id:??) landed as
https://crrev.com/317cb6538c5dcee14dea432fecc9cad5c9d1f605
Cr-Commit-Position: refs/heads/master@{#29313}