[turbofan] Use Start as sentinel for frame states.

[turbofan] Use Start as sentinel for frame states.

This simplifies inlining, in that we only need to update uses of Start
and inputs of End instead of walking the whole inlinee to update all
outer frame states.

R=mstarzinger@chromium.org

Committed: https://crrev.com/7483dbd5fcb9b8a5a4d0b44c9a52eca1b716166f
Cr-Commit-Position: refs/heads/master@{#28649}

[Benedikt Meurer, 2015-05-27 10:39:27]

bmeurer@chromium.org changed reviewers:
+ jarin@chromium.org

[Benedikt Meurer, 2015-05-27 10:39:27]

Hey Michi, Jaro,

Inlining cleanup. Please take a look.

Thanks,
Benedikt

[Jarin, 2015-05-27 10:43:12]

lgtm

[Michael Starzinger, 2015-05-27 11:00:29]

LGTM.

[Benedikt Meurer, 2015-05-27 11:00:38]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2015-05-27 11:00:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1146403008/1

[commit-bot: I haz the power, 2015-05-27 11:01:56]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-27 11:02:10]

Patchset 1 (id:??) landed as
https://crrev.com/7483dbd5fcb9b8a5a4d0b44c9a52eca1b716166f
Cr-Commit-Position: refs/heads/master@{#28649}