[turbofan] Connect loops to end via Terminate during graph building.

[turbofan] Connect loops to end via Terminate during graph building.

This way we don't need to connect (potentially) non-terminating loops
later during control reduction, which saves one forward pass over the
control graph.  Long term we will move the trimming functionality of
the control reducer to the GraphReducer, and get rid of the Finish
method again.

As a bonus, this change also properly rewires Terminate, Throw and
Deoptimize during inlining.

R=mstarzinger@chromium.org

Committed: https://crrev.com/f6fb5eb19796736cb414840652c9868693a5775a
Cr-Commit-Position: refs/heads/master@{#28625}

[Benedikt Meurer, 2015-05-26 11:50:51]

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

[Benedikt Meurer, 2015-05-26 11:50:52]

Michi: This is the Terminate thing we've looked into. Please take a look.
Ben: Please take a look at the control reducer changes.

Thanks,
Benedikt

[titzer, 2015-05-26 11:55:41]

lgtm

[Michael Starzinger, 2015-05-26 12:11:19]

LGTM.

[Michael Starzinger, 2015-05-26 12:11:22]

The CQ bit was checked by mstarzinger@chromium.org

[commit-bot: I haz the power, 2015-05-26 12:11:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1155683004/20001

[commit-bot: I haz the power, 2015-05-26 12:18:02]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-05-26 12:18:19]

Patchset 2 (id:??) landed as
https://crrev.com/f6fb5eb19796736cb414840652c9868693a5775a
Cr-Commit-Position: refs/heads/master@{#28625}