cris: Enable *movsi_internal to set condition codes.

cris: Enable *movsi_internal to set condition codes.

Completion of, and first use of, the CRIS-specific parts of the
condition-code-setting framework, making use of the define_subst
machinery and the cmpelim optimization pass.  This round, just
moves in SImode.  Note the re-use of the cc0 era "cc" attribute
(tweaks needed).

gcc:
	* config/cris/cris.md ("cc"): Comment on new use.
	("cc_enabled"): New attribute.
	("enabled"): Make default fall back to cc_enabled.
	("setnz", "ccnz", "setnzvc", "ccnzvc", "setcc", "cccc"): New
	default_subst_attrs.
	("setnz_subst", "setnzvc_subst", "setcc_subst"): New default_subst.
	("*movsi_internal<setcc><setnz><setnzvc>"): Rename from
	"*movsi_internal".  Correct contents of, and rename attribute
	"cc" to "cc<cccc><ccnz><ccnzvc>".