[MIPS] Optimize opcodes to avoid bubble in pipeline.

Possible bubbles between fetch(ldr) and extract(and).
Excute subsequent instruction(s) in between the bubble by
reordering instructions

Change-Id: Ie046fd005f10ef1be08281642e69e40bab5366c1
Signed-off-by: Douglas Leung <douglas@mips.com>
12 files changed