mips.c (dfhigh, [...]): Remove.

        * 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.

From-SVN: r57368