* target.def (preferred_reload_class): New hook.
	* doc/tm.texi.in (TARGET_PREFERRED_RELOAD_CLASS): Document.
	* doc/tm.texi: Regenerate.
	* targhooks.c (default_preferred_reload_class): New function.
	* targhooks.h (default_preferred_reload_class): Declare.
	* reload.c (find_dummy_reload): Change preferred_class variable type
	from enum reg_class to reg_class_t. Use TARGET_PREFERRED_RELOAD_CLASS
	target hook.
	(find_reloads): Change goal_alternative array type from int to
	reg_class_t. Use TARGET_PREFERRED_RELOAD_CLASS target hook.
	(push_reload, find_reloads_address_part): Use
	TARGET_PREFERRED_RELOAD_CLASS target hook.
	* reload1.c (emit_input_reload_insns): Ditto.
	* ira-costs.c (copy_cost): Use TARGET_PREFERRED_RELOAD_CLASS target
	hook. Change rclass argument and secondary_class variable types from
	'enum reg_class' to reg_class_t.

	* config/i386/i386.h (PREFERRED_RELOAD_CLASS): Remove.
	* config/i386/i386-protos (ix86_preferred_reload_class): Remove.
	* config/i386/i386.c (ix86_preferred_reload_class): Make static.
	Change regclass argument and result types from enum reg_class to
	reg_class_t.
	(TARGET_PREFERRED_RELOAD_CLASS): Define.

From-SVN: r165321