add intrinsics for vld1(q)_x4 and vst1(q)_x4

add intrinsics for vld1(q)_x4 and vst1(q)_x4

This patch adds the intrinsic functions for:
- vld1_<mode>_x4
- vst1_<mode>_x4
- vld1q_<mode>_x4
- vst1q_<mode>_x4

Bootstrapped and tested on aarch64-none-linux-gnu.

Committed on behalf of Sylvia Taylor.

2019-08-22  Sylvia Taylor  <sylvia.taylor@arm.com>

gcc/
	* config/aarch64/aarch64-simd-builtins.def:
	(ld1x4): New.
	(st1x4): Likewise.
	* config/aarch64/aarch64-simd.md:
	(aarch64_ld1x4<VALLDIF:mode>): New pattern.
	(aarch64_st1x4<VALLDIF:mode>): Likewise.
	(aarch64_ld1_x4_<mode>): Likewise.
	(aarch64_st1_x4_<mode>): Likewise.
	* config/aarch64/arm_neon.h:
	(vld1_s8_x4): New function.
	(vld1q_s8_x4): Likewise.
	(vld1_s16_x4): Likewise.
	(vld1q_s16_x4): Likewise.
	(vld1_s32_x4): Likewise.
	(vld1q_s32_x4): Likewise.
	(vld1_u8_x4): Likewise.
	(vld1q_u8_x4): Likewise.
	(vld1_u16_x4): Likewise.
	(vld1q_u16_x4): Likewise.
	(vld1_u32_x4): Likewise.
	(vld1q_u32_x4): Likewise.
	(vld1_f16_x4): Likewise.
	(vld1q_f16_x4): Likewise.
	(vld1_f32_x4): Likewise.
	(vld1q_f32_x4): Likewise.
	(vld1_p8_x4): Likewise.
	(vld1q_p8_x4): Likewise.
	(vld1_p16_x4): Likewise.
	(vld1q_p16_x4): Likewise.
	(vld1_s64_x4): Likewise.
	(vld1_u64_x4): Likewise.
	(vld1_p64_x4): Likewise.
	(vld1q_s64_x4): Likewise.
	(vld1q_u64_x4): Likewise.
	(vld1q_p64_x4): Likewise.
	(vld1_f64_x4): Likewise.
	(vld1q_f64_x4): Likewise.
	(vst1_s8_x4): Likewise.
	(vst1q_s8_x4): Likewise.
	(vst1_s16_x4): Likewise.
	(vst1q_s16_x4): Likewise.
	(vst1_s32_x4): Likewise.
	(vst1q_s32_x4): Likewise.
	(vst1_u8_x4): Likewise.
	(vst1q_u8_x4): Likewise.
	(vst1_u16_x4): Likewise.
	(vst1q_u16_x4): Likewise.
	(vst1_u32_x4): Likewise.
	(vst1q_u32_x4): Likewise.
	(vst1_f16_x4): Likewise.
	(vst1q_f16_x4): Likewise.
	(vst1_f32_x4): Likewise.
	(vst1q_f32_x4): Likewise.
	(vst1_p8_x4): Likewise.
	(vst1q_p8_x4): Likewise.
	(vst1_p16_x4): Likewise.
	(vst1q_p16_x4): Likewise.
	(vst1_s64_x4): Likewise.
	(vst1_u64_x4): Likewise.
	(vst1_p64_x4): Likewise.
	(vst1q_s64_x4): Likewise.
	(vst1q_u64_x4): Likewise.
	(vst1q_p64_x4): Likewise.
	(vst1_f64_x4): Likewise.
	(vst1q_f64_x4): Likewise.

gcc/testsuite/
	* gcc.target/aarch64/advsimd-intrinsics/vld1x4.c: New test.
	* gcc.target/aarch64/advsimd-intrinsics/vst1x4.c: New test.

(cherry picked from commit 391625888d4d97f9016ab9ac04acc55d81f0c26f)