Add -mcpu=power11 support.

Add -mcpu=power11 support.

This patch adds the power11 option to the -mcpu= and -mtune= switches.

This patch treats the power11 like a power10 in terms of costs and reassociation
width.

This patch issues a ".machine power11" to the assembly file if you use
-mcpu=power11.

This patch defines _ARCH_PWR11 if the user uses -mcpu=power11.

2024-03-08  Michael Meissner  <meissner@linux.ibm.com>

gcc/

	* config/rs6000/rs6000-c.cc (rs6000_target_modify_macros): Define
	_ARCH_PWR11 if -mcpu=power11.
	* config/rs6000/rs6000-cpus.def (ISA_POWER11_MASKS_SERVER): New define.
	(POWERPC_MASKS): Add power11 isa bit.
	(power11 cpu): Add power11 definition.
	* rs6000-opts.h (PROCESSOR_POWER11): Add power11 processor.
	* config/rs6000/rs6000-string.cc (expand_compare_loop): Likewise.
	* config/rs6000/rs6000-tables.opt: Regenerate.
	* config/rs6000/rs6000.cc (power11_cost): Add power11 support.
	(rs6000_option_override_internal): Likewise.
	(rs6000_machine_from_flags): Likewise.
	(rs6000_reassociation_width): Likewise.
	(rs6000_adjust_cost): Likewise.
	(rs6000_issue_rate): Likewise.
	(rs6000_sched_reorder): Likewise.
	(rs6000_sched_reorder2): Likewise.
	(rs6000_register_move_cost): Likewise.
	(rs6000_opt_masks): Likewise.
	* config/rs6000/rs6000.md (cpu attribute): Add power11.
	* config/rs6000/rs6000.opt (-mpower11): Add internal power11 ISA flag.
	* doc/invoke.texi (RS/6000 and PowerPC Options): Document -mcpu=power11.