AVX512FP16: Add vreduceph/vreducesh/vrndscaleph/vrndscalesh.

gcc/ChangeLog:

	* config/i386/avx512fp16intrin.h (_mm512_reduce_ph):
	New intrinsic.
	(_mm512_mask_reduce_ph): Likewise.
	(_mm512_maskz_reduce_ph): Likewise.
	(_mm512_reduce_round_ph): Likewise.
	(_mm512_mask_reduce_round_ph): Likewise.
	(_mm512_maskz_reduce_round_ph): Likewise.
	(_mm_reduce_sh): Likewise.
	(_mm_mask_reduce_sh): Likewise.
	(_mm_maskz_reduce_sh): Likewise.
	(_mm_reduce_round_sh): Likewise.
	(_mm_mask_reduce_round_sh): Likewise.
	(_mm_maskz_reduce_round_sh): Likewise.
	(_mm512_roundscale_ph): Likewise.
	(_mm512_mask_roundscale_ph): Likewise.
	(_mm512_maskz_roundscale_ph): Likewise.
	(_mm512_roundscale_round_ph): Likewise.
	(_mm512_mask_roundscale_round_ph): Likewise.
	(_mm512_maskz_roundscale_round_ph): Likewise.
	(_mm_roundscale_sh): Likewise.
	(_mm_mask_roundscale_sh): Likewise.
	(_mm_maskz_roundscale_sh): Likewise.
	(_mm_roundscale_round_sh): Likewise.
	(_mm_mask_roundscale_round_sh): Likewise.
	(_mm_maskz_roundscale_round_sh): Likewise.
	* config/i386/avx512fp16vlintrin.h: (_mm_reduce_ph):
	New intrinsic.
	(_mm_mask_reduce_ph): Likewise.
	(_mm_maskz_reduce_ph): Likewise.
	(_mm256_reduce_ph): Likewise.
	(_mm256_mask_reduce_ph): Likewise.
	(_mm256_maskz_reduce_ph): Likewise.
	(_mm_roundscale_ph): Likewise.
	(_mm_mask_roundscale_ph): Likewise.
	(_mm_maskz_roundscale_ph): Likewise.
	(_mm256_roundscale_ph): Likewise.
	(_mm256_mask_roundscale_ph): Likewise.
	(_mm256_maskz_roundscale_ph): Likewise.
	* config/i386/i386-builtin-types.def: Add corresponding builtin types.
	* config/i386/i386-builtin.def: Add corresponding new builtins.
	* config/i386/i386-expand.c
	(ix86_expand_args_builtin): Handle new builtin types.
	(ix86_expand_round_builtin): Ditto.
	* config/i386/sse.md (<mask_codefor>reducep<mode><mask_name>):
	Renamed to ...
	(<mask_codefor>reducep<mode><mask_name><round_saeonly_name>):
	... this, and adjust for round operands.
	(reduces<mode><mask_scalar_name>): Likewise, with ...
	(reduces<mode><mask_scalar_name><round_saeonly_scalar_name):
	... this.
	(<avx512>_rndscale<mode><mask_name><round_saeonly_name>):
	Adjust for HF vector modes.
	(avx512f_rndscale<mode><mask_scalar_name><round_saeonly_scalar_name>):
	Ditto.
	(*avx512f_rndscale<mode><round_saeonly_name>): Ditto.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/avx-1.c: Add test for new builtins.
	* gcc.target/i386/sse-13.c: Ditto.
	* gcc.target/i386/sse-23.c: Ditto.
	* gcc.target/i386/sse-14.c: Add test for new intrinsics.
	* gcc.target/i386/sse-22.c: Ditto.