[turbofan] Add JSStackCheck into loop bodies.

[turbofan] Add JSStackCheck into loop bodies.

This allows loopy TurboFan code to be interrupted by placing a stack
check (i.e. JSStackCheck node) into each loop. Note that we currently
limit this to non-asm.js code. Also note that stack checks are actually
placed after loop headers and not at back-branches, which allows us to
reuse existing BailoutIds from Crankshaft.

R=titzer@chromium.org

Committed: https://crrev.com/322cfb3589bc122e773fef041254ded514b31b8e
Cr-Commit-Position: refs/heads/master@{#27666}

[titzer, 2015-04-08 09:53:51]

lgtm

[Michael Starzinger, 2015-04-08 12:23:57]

The CQ bit was checked by mstarzinger@chromium.org

[Michael Starzinger, 2015-04-08 12:23:57]

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/1065923002/#ps40001
(title: "Rebased.")

[commit-bot: I haz the power, 2015-04-08 12:24:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1065923002/40001

[commit-bot: I haz the power, 2015-04-08 12:55:02]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-04-08 12:55:10]

Patchset 3 (id:??) landed as
https://crrev.com/322cfb3589bc122e773fef041254ded514b31b8e
Cr-Commit-Position: refs/heads/master@{#27666}