mips16 llvm almost at 100% pass rate in test-suite

I hope I can wrap it up soon.

After my weekend putbacks, I'm down to 0 failures in Single-source and 5 failures in multi-source but have not investigated yet. Sometimes they are gcc mips16 (which is used for comparison results) or other build issues and not really llvm failures.

Mips16 has many nutty problems, especially regards floating point, register set, exception handling, and it's need to seamlessly interoperate with mips32 code (which knows nothing of mips16).