[instruction scheduler] fix ArchDebugBreak.

[instruction scheduler] fix ArchDebugBreak.

In TurboFan the ArchDebugBreak opcode is not used for debugging but to
force a crash in unreachable or unimplemented code path. The opcode was
marked as having no side effects allowing the scheduler to bring it "up"
with unfortunate consequences.

This patch also update the behaviour of assembler::debug when not using
the simulator.

Review-Url: https://codereview.chromium.org/2901383004
Cr-Commit-Position: refs/heads/master@{#45608}
Committed: https://chromium.googlesource.com/v8/v8/+/f56a48e86f662b6a29df26027f3444f696d9622c

[Rodolph Perfetta (ARM), 2017-05-25 22:14:32]

Description was changed from

==========
[instruction scheduler] fix ArchDebugBreak.

In TurboFan the ArchDebugBreak opcode is not used for debugging but to
force a crash in unreachable or unimplemented code path. The opcode was
marked as having no side effects allowing the scheduler to bring it "up"
with unfortunate consequences.

This patch also update the behaviour of assembler::debug when not using
the simulator.

BUG=
==========

to

==========
[instruction scheduler] fix ArchDebugBreak.

In TurboFan the ArchDebugBreak opcode is not used for debugging but to
force a crash in unreachable or unimplemented code path. The opcode was
marked as having no side effects allowing the scheduler to bring it "up"
with unfortunate consequences.

This patch also update the behaviour of assembler::debug when not using
the simulator.
==========

[Rodolph Perfetta (ARM), 2017-05-25 22:14:32]

rodolph.perfetta@arm.com changed reviewers:
+ jarin@chromium.org

[Jarin, 2017-05-29 06:29:21]

lgtm. Thanks!

[Rodolph Perfetta (ARM), 2017-05-30 14:14:41]

The CQ bit was checked by rodolph.perfetta@arm.com

[commit-bot: I haz the power, 2017-05-30 14:14:46]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-05-30 14:44:06]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1496153681683550, "parent_rev":
"9ca164d05114008ba21e7e65da29271392c8efe9", "commit_rev":
"f56a48e86f662b6a29df26027f3444f696d9622c"}

[commit-bot: I haz the power, 2017-05-30 14:44:12]

Description was changed from

==========
[instruction scheduler] fix ArchDebugBreak.

In TurboFan the ArchDebugBreak opcode is not used for debugging but to
force a crash in unreachable or unimplemented code path. The opcode was
marked as having no side effects allowing the scheduler to bring it "up"
with unfortunate consequences.

This patch also update the behaviour of assembler::debug when not using
the simulator.
==========

to

==========
[instruction scheduler] fix ArchDebugBreak.

In TurboFan the ArchDebugBreak opcode is not used for debugging but to
force a crash in unreachable or unimplemented code path. The opcode was
marked as having no side effects allowing the scheduler to bring it "up"
with unfortunate consequences.

This patch also update the behaviour of assembler::debug when not using
the simulator.

Review-Url: https://codereview.chromium.org/2901383004
Cr-Commit-Position: refs/heads/master@{#45608}
Committed:
https://chromium.googlesource.com/v8/v8/+/f56a48e86f662b6a29df26027f3444f696d...
==========

[commit-bot: I haz the power, 2017-05-30 14:44:13]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/v8/v8/+/f56a48e86f662b6a29df26027f3444f696d...