aarch64: Consolidate simd type lookup functions

aarch64: Consolidate simd type lookup functions

There were several similarly-named functions, which each built or looked up an
operand type using a different subset of valid modes or qualifiers.

This change provides a single function to return operand types, which can
additionally handle const and pointer qualifiers.  For clarity, the existing
functionality is kept in separate helper functions.

gcc/ChangeLog:

	* config/aarch64/aarch64-builtins.cc
	(aarch64_simd_builtin_std_type): Rename to...
	(aarch64_int_or_fp_type): ...this, and allow irrelevant qualifiers.
	(aarch64_lookup_simd_builtin_type): Rename to...
	(aarch64_simd_builtin_type): ...this. Add const/pointer
	support, and extract table lookup to...
	(aarch64_lookup_simd_type_in_table): ...this function.
	(aarch64_init_crc32_builtins): Update to use aarch64_simd_builtin_type.
	(aarch64_init_fcmla_laneq_builtins): Ditto.
	(aarch64_init_simd_builtin_functions): Ditto.