MIPS: port Implement for-in loop for proxies.
MIPS: port Implement for-in loop for proxies.

Port r9760 (a1c4dc80)

BUG=
TEST=

Review URL: http://codereview.chromium.org/8396029
Patch from Paul Lind <plind44@gmail.com>.

git-svn-id: b158db1e4b4ab85d4c9e510fdef4b1e8c614b15b@9806 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh