Add initial support for v8_target_arch == "arm" to GN config

Add initial support for v8_target_arch == "arm" to GN config

BUG=none
R=eseidel@chromium.org,brettw@chromium.org,machenbach@chromium.org
LOG=n

Committed: https://crrev.com/d4a69500ed373f6531467762ec20302de2c1dd69
Cr-Commit-Position: refs/heads/master@{#26162}

[jochen (gone - plz use gerrit), 2015-01-20 13:11:29]

Brett, any idea what to do about this:


ERROR at //v8/BUILD.gn:11:20: Assignment had no effect.
arm_test_noprobe = false
                   ^----
You set the variable "arm_test_noprobe" here and it was unused before it went
out of scope.

arm_test_noprobe, however, is referenced in line 123, just not for x64.

I uploaded a new version, that doesn't support this setting (and thus should
work)

[Michael Achenbach, 2015-01-20 13:33:47]

lgtm (rubber-stamp)

Unrelated: The names are a bit confusing... I assume CAN_USE_VFP32DREGS means
VFP3 can use 32 registers? Shouldn't it be called CAN_USE_VFP332DREGS?

[jochen (gone - plz use gerrit), 2015-01-20 13:44:21]

On 2015/01/20 at 13:33:47, machenbach wrote:
> lgtm (rubber-stamp)
> 
> Unrelated: The names are a bit confusing... I assume CAN_USE_VFP32DREGS means
VFP3 can use 32 registers? Shouldn't it be called CAN_USE_VFP332DREGS?

I have no idea

[jochen (gone - plz use gerrit), 2015-01-20 13:44:23]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2015-01-20 13:44:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/863683002/20001

[commit-bot: I haz the power, 2015-01-20 14:34:02]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-01-20 14:34:20]

Patchset 2 (id:??) landed as
https://crrev.com/d4a69500ed373f6531467762ec20302de2c1dd69
Cr-Commit-Position: refs/heads/master@{#26162}

[eseidel, 2015-01-22 18:41:27]

Unfortunately this did not solve the issue. :/