[turbofan] Remove the FloatXXSubPreserveNan operators.

[turbofan] Remove the FloatXXSubPreserveNan operators.

This CL changes the semantics of FloatXXSub to match the semantics of
the semantics of FloatXXSubPreserveNan. Therefore there is no need
anymore for the FloatXXSubPreserveNan operators.

The optimizations in VisitFloatXXSub which are removed in this CL have
already been moved to machine-operator-reducer.cc in
https://codereview.chromium.org/2226663002

R=bmeurer@chromium.org

Committed: https://crrev.com/f8938e50964e7b83818a0fff7fc0f2b065f8bf49
Cr-Commit-Position: refs/heads/master@{#38437}

[ahaas, 2016-08-08 09:11:27]

The CQ bit was checked by ahaas@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-08-08 09:11:34]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Benedikt Meurer, 2016-08-08 09:12:19]

Awesome, LGTM! Thanks.

[commit-bot: I haz the power, 2016-08-08 09:26:05]

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

[commit-bot: I haz the power, 2016-08-08 09:26:06]

Dry run: Try jobs failed on following builders:
  v8_linux64_gyp_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_gyp_rel_ng/build...)
  v8_linux64_gyp_rel_ng_triggered on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_gyp_rel_ng_trigg...)

[ahaas, 2016-08-08 09:39:25]

The CQ bit was checked by ahaas@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-08-08 09:39:33]

Dry run: 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, 2016-08-08 10:18:28]

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

[commit-bot: I haz the power, 2016-08-08 10:18:29]

Dry run: Try jobs failed on following builders:
  v8_linux_arm_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_arm_rel_ng/builds/...)
  v8_linux_arm_rel_ng_triggered on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_arm_rel_ng_trigger...)

[ahaas, 2016-08-08 11:32:25]

The CQ bit was checked by ahaas@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-08-08 11:32:32]

Dry run: 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, 2016-08-08 12:02:12]

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

[commit-bot: I haz the power, 2016-08-08 12:02:13]

Dry run: This issue passed the CQ dry run.

[ahaas, 2016-08-08 12:02:49]

The CQ bit was checked by ahaas@chromium.org

[ahaas, 2016-08-08 12:02:50]

The patchset sent to the CQ was uploaded after l-g-t-m from bmeurer@chromium.org
Link to the patchset: https://codereview.chromium.org/2220973002/#ps30001
(title: "Reintroduce an optimization for arm.")

[commit-bot: I haz the power, 2016-08-08 12:03:00]

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, 2016-08-08 12:09:02]

Committed patchset #3 (id:30001)

[commit-bot: I haz the power, 2016-08-08 12:09:59]

Description was changed from

==========
[turbofan] Remove the FloatXXSubPreserveNan operators.

This CL changes the semantics of FloatXXSub to match the semantics of
the semantics of FloatXXSubPreserveNan. Therefore there is no need
anymore for the FloatXXSubPreserveNan operators.

The optimizations in VisitFloatXXSub which are removed in this CL have
already been moved to machine-operator-reducer.cc in
https://codereview.chromium.org/2226663002

R=bmeurer@chromium.org
==========

to

==========
[turbofan] Remove the FloatXXSubPreserveNan operators.

This CL changes the semantics of FloatXXSub to match the semantics of
the semantics of FloatXXSubPreserveNan. Therefore there is no need
anymore for the FloatXXSubPreserveNan operators.

The optimizations in VisitFloatXXSub which are removed in this CL have
already been moved to machine-operator-reducer.cc in
https://codereview.chromium.org/2226663002

R=bmeurer@chromium.org

Committed: https://crrev.com/f8938e50964e7b83818a0fff7fc0f2b065f8bf49
Cr-Commit-Position: refs/heads/master@{#38437}
==========

[commit-bot: I haz the power, 2016-08-08 12:10:00]

Patchset 3 (id:??) landed as
https://crrev.com/f8938e50964e7b83818a0fff7fc0f2b065f8bf49
Cr-Commit-Position: refs/heads/master@{#38437}