TEST=cctest/test-assembler-mips/MIPS3

BUG=
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/17099010

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15212 ce2b1a6d-e550-0410-aec6-3dcde31c8c00