[MIPS] Fixing FP registers fs0 and fs1 corruption bug.

For performance reasons, we don't want to use "callee saved" FP registers.
The fix is to just use temporary FP registers instead.

Signed-off-by: Douglas Leung <douglas@mips.com>
(cherry picked from commit bd5317a71b13328550968f5cc01ebdd1060299d4)

Change-Id: Ia3608832d9efe1cdea73c1debab7d67d158baa14
rTEMP gets clobbered in the JALR macro. Use t9 instead.

Change-Id: I0ac806c9ad73acf766a8b233997da33b794365be