arm: Add vstN_lane_bf16 + vstNq_lane_bf16 intrisics

arm: Add vstN_lane_bf16 + vstNq_lane_bf16 intrisics

gcc/ChangeLog

2020-10-29  Andrea Corallo  <andrea.corallo@arm.com>

	* config/arm/arm_neon.h (vst2_lane_bf16, vst2q_lane_bf16)
	(vst3_lane_bf16, vst3q_lane_bf16, vst4_lane_bf16)
	(vst4q_lane_bf16): New intrinsics.
	* config/arm/arm_neon_builtins.def: Touch it for:
	__builtin_neon_vst2_lanev4bf, __builtin_neon_vst2_lanev8bf,
	__builtin_neon_vst3_lanev4bf, __builtin_neon_vst3_lanev8bf,
	__builtin_neon_vst4_lanev4bf,__builtin_neon_vst4_lanev8bf.

gcc/testsuite/ChangeLog

2020-10-29  Andrea Corallo  <andrea.corallo@arm.com>

	* gcc.target/aarch64/advsimd-intrinsics/vst2_lane_bf16_indices_1.c:
	Run it also for arm-*-*.
	* gcc.target/aarch64/advsimd-intrinsics/vst2q_lane_bf16_indices_1.c:
	Likewise.
	* gcc.target/aarch64/advsimd-intrinsics/vst3_lane_bf16_indices_1.c:
	Likewise.
	* gcc.target/aarch64/advsimd-intrinsics/vst3q_lane_bf16_indices_1.c:
	Likewise.
	* gcc.target/aarch64/advsimd-intrinsics/vst4_lane_bf16_indices_1.c:
	Likewise.
	* gcc.target/aarch64/advsimd-intrinsics/vst4q_lane_bf16_indices_1.c:
	Likewise.
	* gcc.target/arm/simd/vstn_lane_bf16_1.c: New test.