[AArch64] Add support for float16x{4,8}_t vectors/builtins

[AArch64] Add support for float16x{4,8}_t vectors/builtins

gcc/:

	* config/aarch64/aarch64.c (aarch64_vector_mode_supported_p): Support
	V4HFmode and V8HFmode.
	(aarch64_split_simd_move): Add case for V8HFmode.
	* config/aarch64/aarch64-builtins.c (v4hf_UP, v8hf_UP): Define.
	(aarch64_simd_builtin_std_type): Handle HFmode.
	(aarch64_init_simd_builtin_types): Include Float16x4_t and Float16x8_t.

	* config/aarch64/aarch64-simd.md (mov<mode>, aarch64_get_lane<mode>,
	aarch64_ld1<VALL:mode>, aarch64_st1<VALL:mode): Use VALL_F16 iterator.
	(aarch64_be_ld1<mode>, aarch64_be_st1<mode>): Use VALLDI_F16 iterator.

	* config/aarch64/aarch64-simd-builtin-types.def: Add Float16x4_t,
	Float16x8_t.

	* config/aarch64/aarch64-simd-builtins.def (ld1, st1): Use VALL_F16.
	* config/aarch64/arm_neon.h (float16x4_t, float16x8_t, float16_t):
	New typedefs.
	(vget_lane_f16, vgetq_lane_f16, vset_lane_f16, vsetq_lane_f16,
	vld1_f16, vld1q_f16, vst1_f16, vst1q_f16, vst1_lane_f16,
	vst1q_lane_f16): New.
	* config/aarch64/iterators.md (VD, VQ, VQ_NO2E): Add vectors of HFmode.
	(VALLDI_F16, VALL_F16): New.
	(Vmtype, VEL, VCONQ, VHALF, V_TWO_ELEM, V_THREE_ELEM, V_FOUR_ELEM, q):
	Add cases for V4HF and V8HF.
	(VDBL, VRL2, VRL3, VRL4): Add V4HF case.

gcc/testsuite/:

	* g++.dg/abi/mangle-neon-aarch64.C: Add cases for float16x4_t and
	float16x8_t.
	* gcc.target/aarch64/vset_lane_1.c: Likewise.
	* gcc.target/aarch64/vld1-vst1_1.c: Likewise.
	* gcc.target/aarch64/vld1_lane.c: Likewise.

From-SVN: r227542