[arm] Clean up use of IsSupported and IsEnabled.

[arm] Clean up use of IsSupported and IsEnabled.

CpuFeatures::IsSupported(feature) indicates that the feature is
available on the target. AssemblerBase::IsEnabled(feature) indicates
that we've checked for support (using CpuFeatureScope). The main benefit
is that we can test on (for example) ARMv8, but have some assurance that
we won't generate ARMv8 instructions on ARMv7 targets.

This patch simply cleans up the usage, which had become inconsistent.
The instruction emission functions now check not only that their
dependent features are supported, but also that we've verified that
using CpuFeatureScope.

BUG=

Committed: https://crrev.com/73518a9070896d964fac750793a784f34f5172d3
Cr-Commit-Position: refs/heads/master@{#39676}

[jbramley, 2016-09-22 12:59:27]

jacob.bramley@arm.com changed reviewers:
+ bmeurer@chromium.org, epertoso@chromium.org, jarin@chromium.org

[Benedikt Meurer, 2016-09-23 03:53:10]

lgtm

[jbramley, 2016-09-23 07:15:30]

The CQ bit was checked by jacob.bramley@arm.com

[commit-bot: I haz the power, 2016-09-23 07:15:40]

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, 2016-09-23 09:16:07]

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

[commit-bot: I haz the power, 2016-09-23 09:16:08]

Try jobs failed on following builders:
  v8_win64_rel_ng on master.tryserver.v8 (JOB_TIMED_OUT, no build URL)
  v8_win_compile_dbg on master.tryserver.v8 (JOB_TIMED_OUT, no build URL)
  v8_win_nosnap_shared_rel_ng on master.tryserver.v8 (JOB_TIMED_OUT, no build
URL)
  v8_win_rel_ng on master.tryserver.v8 (JOB_TIMED_OUT, no build URL)

[jbramley, 2016-09-23 09:31:21]

The CQ bit was checked by jacob.bramley@arm.com

[commit-bot: I haz the power, 2016-09-23 09:31:36]

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, 2016-09-23 10:35:50]

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

[commit-bot: I haz the power, 2016-09-23 10:35:51]

Exceeded global retry quota

[jbramley, 2016-09-23 13:52:05]

The CQ bit was checked by jacob.bramley@arm.com

[commit-bot: I haz the power, 2016-09-23 13:52:20]

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, 2016-09-23 15:29:16]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-23 15:29:28]

Description was changed from

==========
[arm] Clean up use of IsSupported and IsEnabled.

CpuFeatures::IsSupported(feature) indicates that the feature is
available on the target. AssemblerBase::IsEnabled(feature) indicates
that we've checked for support (using CpuFeatureScope). The main benefit
is that we can test on (for example) ARMv8, but have some assurance that
we won't generate ARMv8 instructions on ARMv7 targets.

This patch simply cleans up the usage, which had become inconsistent.
The instruction emission functions now check not only that their
dependent features are supported, but also that we've verified that
using CpuFeatureScope.

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

to

==========
[arm] Clean up use of IsSupported and IsEnabled.

CpuFeatures::IsSupported(feature) indicates that the feature is
available on the target. AssemblerBase::IsEnabled(feature) indicates
that we've checked for support (using CpuFeatureScope). The main benefit
is that we can test on (for example) ARMv8, but have some assurance that
we won't generate ARMv8 instructions on ARMv7 targets.

This patch simply cleans up the usage, which had become inconsistent.
The instruction emission functions now check not only that their
dependent features are supported, but also that we've verified that
using CpuFeatureScope.

BUG=

Committed: https://crrev.com/73518a9070896d964fac750793a784f34f5172d3
Cr-Commit-Position: refs/heads/master@{#39676}
==========

[commit-bot: I haz the power, 2016-09-23 15:29:29]

Patchset 1 (id:??) landed as
https://crrev.com/73518a9070896d964fac750793a784f34f5172d3
Cr-Commit-Position: refs/heads/master@{#39676}