Enable vectorization for _Float16 floor/ceil/trunc/nearbyint/rint operations.

Enable vectorization for _Float16 floor/ceil/trunc/nearbyint/rint operations.

gcc/ChangeLog:

	PR target/102464
	* config/i386/i386-builtin-types.def (V8HF_FTYPE_V8HF): New
	function type.
	(V16HF_FTYPE_V16HF): Ditto.
	(V32HF_FTYPE_V32HF): Ditto.
	(V8HF_FTYPE_V8HF_ROUND): Ditto.
	(V16HF_FTYPE_V16HF_ROUND): Ditto.
	(V32HF_FTYPE_V32HF_ROUND): Ditto.
	* config/i386/i386-builtin.def ( IX86_BUILTIN_FLOORPH,
	IX86_BUILTIN_CEILPH, IX86_BUILTIN_TRUNCPH,
	IX86_BUILTIN_FLOORPH256, IX86_BUILTIN_CEILPH256,
	IX86_BUILTIN_TRUNCPH256, IX86_BUILTIN_FLOORPH512,
	IX86_BUILTIN_CEILPH512, IX86_BUILTIN_TRUNCPH512): New builtin.
	* config/i386/i386-builtins.c
	(ix86_builtin_vectorized_function): Enable vectorization for
	HFmode FLOOR/CEIL/TRUNC operation.
	* config/i386/i386-expand.c (ix86_expand_args_builtin): Handle
	new builtins.
	* config/i386/sse.md (rint<mode>2, nearbyint<mode>2): Extend
	to vector HFmodes.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/pr102464-vrndscaleph.c: New test.