[MIPS] Fix method tracing for mips64

Reg $v0 is being clobbered on using
SETUP_REFS_ONLY_CALLEE_SAVE_FRAME inside instrumentation_exit()
trampoline, when falling through from instrumentation_entry().

To fix, use $t1 for ArtMethod* fetching inside SETUP_ macros.

Also fix some unrelated comment errors.

Bug: 21555893

(cherry picked from commit 84bc06e30ba12c3ff07e577c52b63b9df162af7e)

Change-Id: I4ab169f75988c4f0d924416a30196f21c1a043a3
2 files changed