Add -mcpu=future.

Add -mcpu=future.

2022-10-26   Michael Meissner  <meissner@linux.ibm.com>

gcc/

	* config/rs6000/rs6000-cpus.def (ISA_FUTURE_MASKS): New macro.
	(POWERPC_MASKS): Add -mblock-ops-vector-pair.
	* config/rs6000/rs6000-opts.h (enum processor_type): Add
	PROCESSOR_FUTURE.
	* config/rs6000/rs6000-tables.opt: Regenerate.
	* config/rs6000/rs6000.cc (rs6000_option_override_internal): Add
	-mcpu=future support.
	(rs6000_machine_from_flags): Likewise.
	(rs6000_adjust_cost): Likewise.
	(rs6000_issue_rate): Likewise.
	(rs6000_sched_reorder): Likewise.
	(rs6000_sched_reorder2): Likewise.
	(rs6000_register_move_cost): Likewise.
	* config/rs6000/rs6000.h (ASM_CPU_SUPPORT): Likewise.
	* config/rs6000/rs6000.md (cpu attribute): Likewise.