(SignalException): Pass floating point cases to mips16_entry.
(ValueFPR): Don't restrict fmt_single and fmt_word to even
registers.
(StoreFPR): Likewise. Also, don't clobber fpr + 1 for fmt_single
or fmt_word.
(COP_LW): Pass fmt_word rather than fmt_uninterpreted to StoreFPR,
and then set the state to fmt_uninterpreted.
(COP_SW): Temporarily set the state to fmt_word while calling
ValueFPR.