aarch64: Use type-qualified builtins for unsigned MLA/MLS intrinsics

aarch64: Use type-qualified builtins for unsigned MLA/MLS intrinsics

Declare type-qualified builtins and use them for MLA/MLS Neon
intrinsics that operate on unsigned types. This eliminates lots of
casts in arm_neon.h.

gcc/ChangeLog:

2021-11-08  Jonathan Wright  <jonathan.wright@arm.com>

	* config/aarch64/aarch64-simd-builtins.def: Declare type-
	qualified builtin generators for unsigned MLA/MLS intrinsics.
	* config/aarch64/arm_neon.h (vmla_n_u16): Use type-qualified
	builtin.
	(vmla_n_u32): Likewise.
	(vmla_u8): Likewise.
	(vmla_u16): Likewise.
	(vmla_u32): Likewise.
	(vmlaq_n_u16): Likewise.
	(vmlaq_n_u32): Likewise.
	(vmlaq_u8): Likewise.
	(vmlaq_u16): Likewise.
	(vmlaq_u32): Likewise.
	(vmls_n_u16): Likewise.
	(vmls_n_u32): Likewise.
	(vmls_u8): Likewise.
	(vmls_u16): Likewise.
	(vmls_u32): Likewise.
	(vmlsq_n_u16): Likewise.
	(vmlsq_n_u32): Likewise.
	(vmlsq_u8): Likewise.
	(vmlsq_u16): Likewise.
	(vmlsq_u32): Likewise.