Recognize shuffle patterns for REV instructions on AArch64, rewrite intrinsics.

Recognize shuffle patterns for REV instructions on AArch64, rewrite intrinsics.

        * config/aarch64/aarch64-simd.md (aarch64_rev<REVERSE:rev-op><mode>):
        New pattern.
        * config/aarch64/aarch64.c (aarch64_evpc_rev): New function.
        (aarch64_expand_vec_perm_const_1): Add call to aarch64_evpc_rev.
        * config/aarch64/iterators.md (REVERSE): New iterator.
        (UNSPEC_REV64, UNSPEC_REV32, UNSPEC_REV16): New enum elements.
        (rev_op): New int_attribute.
        * config/aarch64/arm_neon.h (vrev16_p8, vrev16_s8, vrev16_u8,
        vrev16q_p8, vrev16q_s8, vrev16q_u8, vrev32_p8, vrev32_p16, vrev32_s8,
        vrev32_s16, vrev32_u8, vrev32_u16, vrev32q_p8, vrev32q_p16, vrev32q_s8,
        vrev32q_s16, vrev32q_u8, vrev32q_u16, vrev64_f32, vrev64_p8,
        vrev64_p16, vrev64_s8, vrev64_s16, vrev64_s32, vrev64_u8, vrev64_u16,
        vrev64_u32, vrev64q_f32, vrev64q_p8, vrev64q_p16, vrev64q_s8,
        vrev64q_s16, vrev64q_s32, vrev64q_u8, vrev64q_u16, vrev64q_u32):
        Replace temporary __asm__ with __builtin_shuffle.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@211174 138bc75d-0d04-0410-961f-82ee72b054a4