re PR target/18331 (mmix-knuth-mmixware testsuite failure: execute/ieee/fp-cmp-8.c gcc.dg/20040625-1.c)

	PR target/18331
	* config/mmix/mmix.md ("*movdicc_real_reversible"): Rename from
	"*movdicc_real".  Only match reversible comparisons.
	("*movdicc_real_nonreversible"): New pattern, split from
	"*movdicc_real".  Match only nonreversible comparisons.  Exclude
	reversed alternatives.
	("*movdfcc_real_reversible", "*movdfcc_real_nonreversible"):
	Similar.

From-SVN: r91416