* config/mips/mips.c (dfhigh, dflow, sfhigh, sflow): Remove.
(override_options): Do not initialize them.
(mips_const_double_ok): Allow no fp constants except zero,
and not even that for mips16.
(const_float_1_operand): Use dconst1.
* config/mips/mips.md (movsf, movsf_internal1, movsf_internal2,
movdf, movdf_internal1, movdf_internal1a, movdf_internal2):
Don't allow arbitrary constants; fix predicates and C constraint.