MIPS: Minor-key-ify four stubs.

Port r23605 (8fcd377)

Original commit message:
- ICCompareStub
- BinaryOpICStub
- CompareNilICStub
- VectorLoadStub

BUG=
R=paul.lind@imgtec.com

Review URL: https://codereview.chromium.org/531033003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23623 ce2b1a6d-e550-0410-aec6-3dcde31c8c00