[turbofan] Fix bug in OSR deconstruction.

[turbofan] Fix bug in OSR deconstruction.

In constructing the transfer between loop copies, we need to merge the backedges from all the previous copies of the given loop. The control reduction will work out which ones are really reachable.

R=mstarzinger@chromium.org
BUG=

Committed: https://crrev.com/434d1ad0146d63120b26938983fa6b1606c3e7a7
Cr-Commit-Position: refs/heads/master@{#27246}

[Michael Starzinger, 2015-03-17 16:30:04]

LGTM.

https://codereview.chromium.org/1004993004/diff/60001/src/compiler/osr.cc
File src/compiler/osr.cc (right):

https://codereview.chromium.org/1004993004/diff/60001/src/compiler/osr.cc#new...
src/compiler/osr.cc:36: if (TRACE_COND) do {     \
nit: Shouldn't the if-statement go into the do-while-false?

[titzer, 2015-03-17 16:41:29]

https://codereview.chromium.org/1004993004/diff/60001/src/compiler/osr.cc
File src/compiler/osr.cc (right):

https://codereview.chromium.org/1004993004/diff/60001/src/compiler/osr.cc#new...
src/compiler/osr.cc:36: if (TRACE_COND) do {     \
On 2015/03/17 16:30:04, Michael Starzinger wrote:
> nit: Shouldn't the if-statement go into the do-while-false?

Done.

[titzer, 2015-03-17 16:43:15]

The CQ bit was checked by titzer@chromium.org

[titzer, 2015-03-17 16:43:16]

The patchset sent to the CQ was uploaded after l-g-t-m from
mstarzinger@chromium.org
Link to the patchset: https://codereview.chromium.org/1004993004/#ps80001
(title: " ")

[commit-bot: I haz the power, 2015-03-17 16:43:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1004993004/80001

[commit-bot: I haz the power, 2015-03-17 17:55:27]

Committed patchset #5 (id:80001)

[commit-bot: I haz the power, 2015-03-17 17:55:35]

Patchset 5 (id:??) landed as
https://crrev.com/434d1ad0146d63120b26938983fa6b1606c3e7a7
Cr-Commit-Position: refs/heads/master@{#27246}