Port r10056 (ffa6eedd8).

Original commit message:
This just ports r10036 to the ARM codegenerator. Please see the original
revision for a detailed description.

BUG=
TEST=

Review URL: http://codereview.chromium.org/8747011
Patch from Daniel Kalmar <kalmard@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10124 ce2b1a6d-e550-0410-aec6-3dcde31c8c00