mips: added emit methods for c.ult.s and movt.s
mips: convfl: add check for the case where value < INT_MIN

For values that are less than INT_MIN, trunc.w.s converts to INT_MAX, but we
want INT_MIN.
mips: swapl: handle float params
mips: fix bug in handling of doubles in loadpq
fixup! mips: let swapq handle doubles