Set the default compiler for X87 to GCC.

Set the default compiler for X87 to GCC.

Compiling v8 for X87 platform with clang compiler leads to some test case failure.
So we set the default compiler for X87 to GCC.

BUG=

Committed: https://crrev.com/536b7cf243ce7bfcaffa8627d1c9fceeef1e5664
Cr-Commit-Position: refs/heads/master@{#27706}

[chunyang.dai, 2015-03-26 14:39:00]

Patchset #2 (id:20001) has been deleted

[chunyang.dai, 2015-04-09 06:18:19]

chunyang.dai@intel.com changed reviewers:
+ danno@chromium.org, machenbach@chromium.org, weiliang.lin@intel.com

[chunyang.dai, 2015-04-09 06:18:20]

PTAL.

[Weiliang, 2015-04-09 06:55:06]

LGTM, but still need danno&Michael's

https://codereview.chromium.org/1031793002/diff/1/build/standalone.gypi
File build/standalone.gypi (right):

https://codereview.chromium.org/1031793002/diff/1/build/standalone.gypi#newco...
build/standalone.gypi:151: 
remove this empty line.

[Michael Achenbach, 2015-04-09 07:38:33]

I'd be happier if the root cause was found why gcc and clang are different
here...

Principally lg, but we'd need to setup a different slave for the bot first as we
require gcc 4.8 and the current slave is not on Trusty yet...

[chunyang.dai, 2015-04-09 07:55:36]

Hi, Michael.
If we use clang to build Release X87 V8. Two test case failed and the reason is
that clang
has aggressive fp optimization. FP load/store in x87 register has its expected
SNAN->QNAN 
conversion and this conversion sometimes is expected. clang's aggressive fp
optimization
 sometimes will use integer register to handle the float value. When  memory
form(or integer
 register form) sNAN is bitwise comparing with a x87-register-form sNAN, it will
fail.

Another reason is that if we use the default clang (version is 3.7.0, downloaded
by "gclient sync")
 to compile Debug V8 X87 on our local machine, Clang will fail. According to
clang code,
It seems it has the assumption that the target platform has either SSE2 or AVX
support when generating
code for integer_to_double conversion. X87 platform has no SSE and AVX. And it
failed. 

sorry to introduce more effort to setup the different bot slave.

[Michael Achenbach, 2015-04-09 08:38:03]

I'll set up different compiler/tester bots and move the first to a trusty slave.
I'll let you know when this can land.

[Michael Achenbach, 2015-04-09 09:14:14]

This depends on https://codereview.chromium.org/1076723002/ to land and a master
restart.

[Michael Achenbach, 2015-04-09 13:03:49]

LGTM - this can land now

[Michael Achenbach, 2015-04-09 13:04:06]

The CQ bit was checked by machenbach@chromium.org

[Michael Achenbach, 2015-04-09 13:04:06]

The patchset sent to the CQ was uploaded after l-g-t-m from
weiliang.lin@intel.com
Link to the patchset: https://codereview.chromium.org/1031793002/#ps40001
(title: " ")

[commit-bot: I haz the power, 2015-04-09 13:04:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1031793002/40001

[Michael Achenbach, 2015-04-09 13:06:26]

The CQ bit was unchecked by machenbach@chromium.org

[Michael Achenbach, 2015-04-09 13:06:41]

The CQ bit was checked by machenbach@chromium.org

[commit-bot: I haz the power, 2015-04-09 13:06:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1031793002/40001

[commit-bot: I haz the power, 2015-04-09 13:26:34]

Committed patchset #2 (id:40001)

[commit-bot: I haz the power, 2015-04-09 13:26:47]

Patchset 2 (id:??) landed as
https://crrev.com/536b7cf243ce7bfcaffa8627d1c9fceeef1e5664
Cr-Commit-Position: refs/heads/master@{#27706}