The patch implements mtc1/mfc1 instructions which are required for GP to/from FP registers moves.
The patch also implements fptosi and sitofp for float and i32 types to test mtc1/mfc1 instructions.

R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/2316933002 .

Patch from Jaydeep Patil <jaydeep.patil@imgtec.com>.