[wasm] Move the semaphore for parallel compilation to the wasm module.

[wasm] Move the semaphore for parallel compilation to the wasm module.

If the semaphore is stored as a local variable in {CompileInParallel},
then the semaphore was sometimes deallocated too early and caused
the compilation tasks to crash. This only happens with libc-2.19,
libc-2.21 fixes the problem.

R=mlippautz@chromium.org, rossberg@chromium.org

Committed: https://crrev.com/d4d470326668a69a3d00cae51ae96d375f862d95
Cr-Commit-Position: refs/heads/master@{#37183}

[Michael Lippautz, 2016-06-22 10:34:47]

lgtm from my side

https://codereview.chromium.org/2080223006/diff/1/src/base/platform/semaphore.cc
File src/base/platform/semaphore.cc (right):

https://codereview.chromium.org/2080223006/diff/1/src/base/platform/semaphore...
src/base/platform/semaphore.cc:104: // This check may fail with libc-2.19, which
we use on the try bots, if the
nit: Maybe just write that it fails for <libc-2.21?

[rossberg, 2016-06-22 11:12:59]

lgtm

[ahaas, 2016-06-22 11:26:33]

The CQ bit was checked by ahaas@chromium.org

[ahaas, 2016-06-22 11:26:33]

The patchset sent to the CQ was uploaded after l-g-t-m from
mlippautz@chromium.org
Link to the patchset: https://codereview.chromium.org/2080223006/#ps20001
(title: "Adjusted a comment.")

[commit-bot: I haz the power, 2016-06-22 11:26:42]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2080223006/20001

[commit-bot: I haz the power, 2016-06-22 11:28:26]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-06-22 11:31:11]

Description was changed from

==========
[wasm] Move the semaphore for parallel compilation to the wasm module.

If the semaphore is stored as a local variable in {CompileInParallel},
then the semaphore was sometimes deallocated too early and caused
the compilation tasks to crash. This only happens with libc-2.19,
libc-2.21 fixes the problem.

R=mlippautz@chromium.org, rossberg@chromium.org
==========

to

==========
[wasm] Move the semaphore for parallel compilation to the wasm module.

If the semaphore is stored as a local variable in {CompileInParallel},
then the semaphore was sometimes deallocated too early and caused
the compilation tasks to crash. This only happens with libc-2.19,
libc-2.21 fixes the problem.

R=mlippautz@chromium.org, rossberg@chromium.org

Committed: https://crrev.com/d4d470326668a69a3d00cae51ae96d375f862d95
Cr-Commit-Position: refs/heads/master@{#37183}
==========

[commit-bot: I haz the power, 2016-06-22 11:31:12]

Patchset 2 (id:??) landed as
https://crrev.com/d4d470326668a69a3d00cae51ae96d375f862d95
Cr-Commit-Position: refs/heads/master@{#37183}