mmix.md ("*call_real"): Fix typo in comment.

mmix.md ("*call_real"): Fix typo in comment.

	* config/mmix/mmix.md ("*call_real"): Fix typo in comment.
	* config/mmix/mmix.h (EXTRA_CONSTRAINT): Pass MMIX_REG_OK_STRICT
	to mmix_extra_constraint.
	* config/mmix/mmix.c (mmix_secondary_reload_class): Only handle
	non-global register classes.  Mark now unused parameters as such.
	(mmix_extra_constraint, 'U'): Use new parameter strict and call
	calling memory_operand_p or strict_memory_address_p, not
	address_operand.
	* config/mmix/mmix-protos.h (mmix_extra_constraint): Add parameter.

From-SVN: r48402