[ARM][GCC][1/5x]: MVE store intrinsics.

[ARM][GCC][1/5x]: MVE store intrinsics.

This patch supports the following MVE ACLE store intrinsics.

vstrbq_scatter_offset_s8, vstrbq_scatter_offset_s32, vstrbq_scatter_offset_s16, vstrbq_scatter_offset_u8, vstrbq_scatter_offset_u32, vstrbq_scatter_offset_u16, vstrbq_s8, vstrbq_s32, vstrbq_s16, vstrbq_u8, vstrbq_u32, vstrbq_u16, vstrwq_scatter_base_s32, vstrwq_scatter_base_u32.

Please refer to M-profile Vector Extension (MVE) intrinsics [1]  for more details.
[1]  https://developer.arm.com/architectures/instruction-sets/simd-isas/helium/mve-intrinsics

2020-03-18  Andre Vieira  <andre.simoesdiasvieira@arm.com>
            Mihail Ionescu  <mihail.ionescu@arm.com>
            Srinath Parvathaneni  <srinath.parvathaneni@arm.com>

	* config/arm/arm-builtins.c (STRS_QUALIFIERS): Define builtin qualifier.
	(STRU_QUALIFIERS): Likewise.
	(STRSS_QUALIFIERS): Likewise.
	(STRSU_QUALIFIERS): Likewise.
	(STRSBS_QUALIFIERS): Likewise.
	(STRSBU_QUALIFIERS): Likewise.
	* config/arm/arm_mve.h (vstrbq_s8): Define macro.
	(vstrbq_u8): Likewise.
	(vstrbq_u16): Likewise.
	(vstrbq_scatter_offset_s8): Likewise.
	(vstrbq_scatter_offset_u8): Likewise.
	(vstrbq_scatter_offset_u16): Likewise.
	(vstrbq_s16): Likewise.
	(vstrbq_u32): Likewise.
	(vstrbq_scatter_offset_s16): Likewise.
	(vstrbq_scatter_offset_u32): Likewise.
	(vstrbq_s32): Likewise.
	(vstrbq_scatter_offset_s32): Likewise.
	(vstrwq_scatter_base_s32): Likewise.
	(vstrwq_scatter_base_u32): Likewise.
	(__arm_vstrbq_scatter_offset_s8): Define intrinsic.
	(__arm_vstrbq_scatter_offset_s32): Likewise.
	(__arm_vstrbq_scatter_offset_s16): Likewise.
	(__arm_vstrbq_scatter_offset_u8): Likewise.
	(__arm_vstrbq_scatter_offset_u32): Likewise.
	(__arm_vstrbq_scatter_offset_u16): Likewise.
	(__arm_vstrbq_s8): Likewise.
	(__arm_vstrbq_s32): Likewise.
	(__arm_vstrbq_s16): Likewise.
	(__arm_vstrbq_u8): Likewise.
	(__arm_vstrbq_u32): Likewise.
	(__arm_vstrbq_u16): Likewise.
	(__arm_vstrwq_scatter_base_s32): Likewise.
	(__arm_vstrwq_scatter_base_u32): Likewise.
	(vstrbq): Define polymorphic variant.
	(vstrbq_scatter_offset): Likewise.
	(vstrwq_scatter_base): Likewise.
	* config/arm/arm_mve_builtins.def (STRS_QUALIFIERS): Use builtin
	qualifier.
	(STRU_QUALIFIERS): Likewise.
	(STRSS_QUALIFIERS): Likewise.
	(STRSU_QUALIFIERS): Likewise.
	(STRSBS_QUALIFIERS): Likewise.
	(STRSBU_QUALIFIERS): Likewise.
	* config/arm/mve.md (MVE_B_ELEM): Define mode attribute iterator.
	(VSTRWSBQ): Define iterators.
	(VSTRBSOQ): Likewise.
	(VSTRBQ): Likewise.
	(mve_vstrbq_<supf><mode>): Define RTL pattern.
	(mve_vstrbq_scatter_offset_<supf><mode>): Likewise.
	(mve_vstrwq_scatter_base_<supf>v4si): Likewise.

gcc/testsuite/ChangeLog:

2020-03-18  Andre Vieira  <andre.simoesdiasvieira@arm.com>
            Mihail Ionescu  <mihail.ionescu@arm.com>
            Srinath Parvathaneni  <srinath.parvathaneni@arm.com>

	* gcc.target/arm/mve/intrinsics/vstrbq_s16.c: New test.
	* gcc.target/arm/mve/intrinsics/vstrbq_s32.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vstrbq_s8.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vstrbq_scatter_offset_s16.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vstrbq_scatter_offset_s32.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vstrbq_scatter_offset_s8.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vstrbq_scatter_offset_u16.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vstrbq_scatter_offset_u32.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vstrbq_scatter_offset_u8.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vstrbq_u16.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vstrbq_u32.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vstrbq_u8.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vstrwq_scatter_base_s32.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vstrwq_scatter_base_u32.c: Likewise.