[crankshaft] Fix invalid number truncation assumption on HAdd inputs.

[crankshaft] Fix invalid number truncation assumption on HAdd inputs.

In Crankshaft we don't know reliably know that an HAdd might not turn
into a string addition later (via deoptimization), so we cannot set the
HValue::kAllowUndefinedAsNaN flag on the HAdd instruction in those
cases. It doesn't seem to affect performance if we just remove the flag
completely from the HAdd instruction, so let's stick to that approach
for now.

R=jarin@chromium.org
BUG=v8:5074
Committed: https://crrev.com/f576e29c475d104d93176042d2a79066ad8f638c
Cr-Commit-Position: refs/heads/master@{#36805}

[Jarin, 2016-06-07 13:03:24]

lgtm. Thanks!

[Benedikt Meurer, 2016-06-07 13:03:34]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2016-06-07 13:03:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2048643002/1

[commit-bot: I haz the power, 2016-06-07 13:18:37]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-06-07 13:18:38]

Try jobs failed on following builders:
  v8_linux64_asan_rel_ng on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_asan_rel_ng/buil...)
  v8_linux64_asan_rel_ng_triggered on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_asan_rel_ng_trig...)

[Benedikt Meurer, 2016-06-08 03:29:37]

The CQ bit was checked by bmeurer@chromium.org

[Benedikt Meurer, 2016-06-08 03:29:37]

The patchset sent to the CQ was uploaded after l-g-t-m from jarin@chromium.org
Link to the patchset: https://codereview.chromium.org/2048643002/#ps20001
(title: "Refine the flag handling to not introduce deopt loops.")

[commit-bot: I haz the power, 2016-06-08 03:29:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2048643002/20001

[commit-bot: I haz the power, 2016-06-08 03:55:33]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-06-08 03:56:27]

Description was changed from

==========
[crankshaft] Fix invalid number truncation assumption on HAdd inputs.

In Crankshaft we don't know reliably know that an HAdd might not turn
into a string addition later (via deoptimization), so we cannot set the
HValue::kAllowUndefinedAsNaN flag on the HAdd instruction in those
cases. It doesn't seem to affect performance if we just remove the flag
completely from the HAdd instruction, so let's stick to that approach
for now.

R=jarin@chromium.org
BUG=v8:5074
==========

to

==========
[crankshaft] Fix invalid number truncation assumption on HAdd inputs.

In Crankshaft we don't know reliably know that an HAdd might not turn
into a string addition later (via deoptimization), so we cannot set the
HValue::kAllowUndefinedAsNaN flag on the HAdd instruction in those
cases. It doesn't seem to affect performance if we just remove the flag
completely from the HAdd instruction, so let's stick to that approach
for now.

R=jarin@chromium.org
BUG=v8:5074

Committed: https://crrev.com/f576e29c475d104d93176042d2a79066ad8f638c
Cr-Commit-Position: refs/heads/master@{#36805}
==========

[commit-bot: I haz the power, 2016-06-08 03:56:29]

Patchset 2 (id:??) landed as
https://crrev.com/f576e29c475d104d93176042d2a79066ad8f638c
Cr-Commit-Position: refs/heads/master@{#36805}