Remove hard_reg_set_equal_p

Use "x == y" instead of "hard_reg_set_equal_p (x, y)".

2019-09-09  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* hard-reg-set.h (HARD_REG_SET::operator==): New function.
	(HARD_REG_SET::operator!=): Likewise.
	(hard_reg_set_equal_p): Delete.
	* cfgcleanup.c (old_insns_match_p): Use == instead of
	hard_reg_set_equal_p and != instead of !hard_reg_set_equal_p.
	* ira-color.c (allocno_hard_regs_hasher::equal): Likewise.
	(add_allocno_hard_regs_to_forest): Likewise.
	(setup_allocno_available_regs_num): Likewise.
	* ira.c (setup_pressure_classes): Likewise.
	(setup_allocno_and_important_classes): Likewise.
	(setup_reg_class_relations): Likewise.
	* lra-lives.c (process_bb_lives): Likewise.
	* reg-stack.c (change_stack, convert_regs_1): Likewise.

From-SVN: r275534