[MIPS] Do not use compact branches until GDB supports them

GDB does not yet have support for compact branches, and is not able
to set a breakpoint on rtld_db_dlactivity(), which is compiled into
one JIC instruction. Unfortunately, We cannot turn off generation of
JIC compact branch. Instead, add unoptimized FP handling code, so GDB
will have something to land on.

Change-Id: Iddcf40ec018972398179018d049b8323fcd258b7