Patch from ARM Ltd.

BUG=none
TEST=Added to cctest/test-assembler-arm.cc and cctest/test-disasm-arm.cc

Review URL: http://codereview.chromium.org/6625084

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7174 ce2b1a6d-e550-0410-aec6-3dcde31c8c00