X87: [builtins] Make sure argument count is always valid for C++ builtins.

X87: [builtins] Make sure argument count is always valid for C++ builtins.

    port 9c8262f11e3d6359874a63f25a31c6ddfba3dc1c (r31120).

    original commit message:
    When calling into C++ builtins, we need to make sure that the argument
    count register contains the correct number of arguments, otherwise the
    CEntryStub will not be able to leave the stack in the correct state.

BUG=

Committed: https://crrev.com/b64c1f02ad9a42337bfcb306f02fd2709f7b38b1
Cr-Commit-Position: refs/heads/master@{#31503}

[zhengxing.li, 2015-10-23 09:06:09]

zhengxing.li@intel.com changed reviewers:
+ chunyang.dai@intel.com, weiliang.lin@intel.com

[Weiliang, 2015-10-23 09:11:03]

The CQ bit was checked by weiliang.lin@intel.com

[Weiliang, 2015-10-23 09:11:04]

lgtm

[commit-bot: I haz the power, 2015-10-23 09:11:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1418533009/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1418533009/1

[commit-bot: I haz the power, 2015-10-23 09:42:49]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-23 09:43:15]

Patchset 1 (id:??) landed as
https://crrev.com/b64c1f02ad9a42337bfcb306f02fd2709f7b38b1
Cr-Commit-Position: refs/heads/master@{#31503}