This patch supports following MVE ACLE vaddq intrinsics. The RTL patterns for this intrinsics are added using arithmetic "plus" operator.

vaddq_s8, vaddq_s16, vaddq_s32, vaddq_u8, vaddq_u16, vaddq_u32, vaddq_f16, vaddq_f32.

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

2020-03-20  Srinath Parvathaneni  <srinath.parvathaneni@arm.com>
            Andre Vieira  <andre.simoesdiasvieira@arm.com>
            Mihail Ionescu  <mihail.ionescu@arm.com>

	* config/arm/arm_mve.h (vaddq_s8): Define macro.
	(vaddq_s16): Likewise.
	(vaddq_s32): Likewise.
	(vaddq_u8): Likewise.
	(vaddq_u16): Likewise.
	(vaddq_u32): Likewise.
	(vaddq_f16): Likewise.
	(vaddq_f32): Likewise.
	(__arm_vaddq_s8): Define intrinsic.
	(__arm_vaddq_s16): Likewise.
	(__arm_vaddq_s32): Likewise.
	(__arm_vaddq_u8): Likewise.
	(__arm_vaddq_u16): Likewise.
	(__arm_vaddq_u32): Likewise.
	(__arm_vaddq_f16): Likewise.
	(__arm_vaddq_f32): Likewise.
	(vaddq): Define polymorphic variant.
	* config/arm/iterators.md (VNIM): Define mode iterator for common types
	Neon, IWMMXT and MVE.
	(VNINOTM): Likewise.
	* config/arm/mve.md (mve_vaddq<mode>): Define RTL pattern.
	(mve_vaddq_f<mode>): Define RTL pattern.
	* config/arm/neon.md (add<mode>3): Rename to addv4hf3 RTL pattern.
	(addv8hf3_neon): Define RTL pattern.
	* config/arm/vec-common.md (add<mode>3): Modify standard add RTL pattern
	to support MVE.
	(addv8hf3): Define standard RTL pattern for MVE and Neon.
	(add<mode>3): Modify existing standard add RTL pattern for Neon and IWMMXT.

gcc/testsuite/ChangeLog:

2020-03-20  Srinath Parvathaneni  <srinath.parvathaneni@arm.com>
            Andre Vieira  <andre.simoesdiasvieira@arm.com>
            Mihail Ionescu  <mihail.ionescu@arm.com>

	* gcc.target/arm/mve/intrinsics/vaddq_f16.c: New test.
	* gcc.target/arm/mve/intrinsics/vaddq_f32.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vaddq_s16.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vaddq_s32.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vaddq_s8.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vaddq_u16.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vaddq_u32.c: Likewise.
	* gcc.target/arm/mve/intrinsics/vaddq_u8.c: Likewise.