x86: Add cost model for operation of mask registers.

x86: Add cost model for operation of mask registers.

gcc/

	PR target/71453
	* config/i386/i386.h (struct processor_costs): Add member
	mask_to_integer, integer_to_mask, mask_load[3], mask_store[3],
	mask_move.
	* config/i386/x86-tune-costs.h (ix86_size_cost, i386_cost,
	i386_cost, pentium_cost, lakemont_cost, pentiumpro_cost,
	geode_cost, k6_cost, athlon_cost, k8_cost, amdfam10_cost,
	bdver_cost, znver1_cost, znver2_cost, skylake_cost,
	btver1_cost, btver2_cost, pentium4_cost, nocona_cost,
	atom_cost, slm_cost, intel_cost, generic_cost, core_cost):
	Initialize mask_load[3], mask_store[3], mask_move,
	integer_to_mask, mask_to_integer for all target costs.
	* config/i386/i386.c (ix86_register_move_cost): Using cost
	model of mask registers.
	(inline_memory_move_cost): Ditto.
	(ix86_register_move_cost): Ditto.