rs6000: Delete the "wH" and "wI" constraints

rs6000: Delete the "wH" and "wI" constraints

This replaces "wH" by "v", "wI" by "d", and when both are allowed it
uses "wa"; all with isa "p8v".

	* config/rs6000/constraints.md (define_register_constraint "wH"):
	Delete.
	(define_register_constraint "wI"): Delete.
	* config/rs6000/rs6000.h (enum r6000_reg_class_enum): Delete
	RS6000_CONSTRAINT_wH and RS6000_CONSTRAINT_wI.
	* config/rs6000/rs6000.c (rs6000_debug_reg_global): Adjust.
	(rs6000_init_hard_regno_mode_ok): Adjust.
	* config/rs6000/rs6000.md: Replace "wH" and "wI" constraints by "v"
	resp. "d", or with "wa" as appropriate, all with "p8v".
	* config/rs6000/vsx.md: Ditto.
	* doc/md.texi (Machine Constraints): Adjust.

From-SVN: r271390