Since the last ping, I've tweaked the test cases a bit...

Since I've been working on doing the same changes for the ARM backend,
I've moved the tests into the advsimd-intrinsics directory, marked as
XFAIL for ARM targets for now. The gcc/ part of the patch is
unchanged.

gcc/ChangeLog:

<DATE>  Charles Baylis  <charles.baylis@linaro.org>

    PR target/63870
    * config/aarch64/aarch64-builtins.c (enum aarch64_type_qualifiers):
    Add qualifier_struct_load_store_lane_index.
    (aarch64_types_loadstruct_lane_qualifiers): Use
    qualifier_struct_load_store_lane_index for lane index argument for
    last argument.
    (aarch64_types_storestruct_lane_qualifiers): Ditto.
    (builtin_simd_arg): Add SIMD_ARG_STRUCT_LOAD_STORE_LANE_INDEX.
    (aarch64_simd_expand_args): Add new argument describing mode of
    builtin. Check lane bounds for arguments with
    SIMD_ARG_STRUCT_LOAD_STORE_LANE_INDEX.
    (aarch64_simd_expand_builtin): Emit error for incorrect lane indices
    if marked with SIMD_ARG_STRUCT_LOAD_STORE_LANE_INDEX.
    (aarch64_simd_expand_builtin): Handle arguments with
    qualifier_struct_load_store_lane_index. Pass machine mode of builtin to
    aarch64_simd_expand_args.
    * config/aarch64/aarch64-simd-builtins.def: Declare ld[234]_lane and
    vst[234]_lane with BUILTIN_VALLDIF.
    * config/aarch64/aarch64-simd.md:
    (aarch64_vec_load_lanesoi_lane<mode>): Use VALLDIF iterator. Perform
    endianness reversal on lane index.
    (aarch64_vec_load_lanesci_lane<mode>): Ditto.
    (aarch64_vec_load_lanesxi_lane<mode>): Ditto.
    (vec_store_lanesoi_lane<mode>): Use VALLDIF iterator. Fix typo
    in attribute.
    (vec_store_lanesci_lane<mode>): Use VALLDIF iterator.
    (vec_store_lanesxi_lane<mode>): Ditto.
    (aarch64_ld2_lane<mode>): Use VALLDIF iterator. Remove endianness
    reversal of lane index.
    (aarch64_ld3_lane<mode>): Ditto.
    (aarch64_ld4_lane<mode>): Ditto.
    (aarch64_st2_lane<mode>): Ditto.
    (aarch64_st3_lane<mode>): Ditto.
    (aarch64_st4_lane<mode>): Ditto.
    * config/aarch64/arm_neon.h (__LD2_LANE_FUNC): Rename mode parameter
    to qmode. Add new mode parameter. Update uses.
           (__LD3_LANE_FUNC): Ditto.
    (__LD4_LANE_FUNC): Ditto.
    (__ST2_LANE_FUNC): Ditto.
    (__ST3_LANE_FUNC): Ditto.
    (__ST4_LANE_FUNC): Ditto.

gcc/testsuite/ChangeLog:

<DATE>  Charles Baylis  <charles.baylis@linaro.org>

gcc/testsuite/ChangeLog:

<DATE>  Charles Baylis  <charles.baylis@linaro.org>

        * gcc.target/aarch64/advsimd-intrinsics/vld2_lane_f32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2_lane_f64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2_lane_p8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2_lane_s16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2_lane_s32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2_lane_s64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2_lane_s8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2_lane_u16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2_lane_u32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2_lane_u64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2_lane_u8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2q_lane_f32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2q_lane_f64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2q_lane_p8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2q_lane_s16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2q_lane_s32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2q_lane_s64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2q_lane_s8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2q_lane_u16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2q_lane_u32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2q_lane_u64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld2q_lane_u8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3_lane_f32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3_lane_f64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3_lane_p8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3_lane_s16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3_lane_s32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3_lane_s64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3_lane_s8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3_lane_u16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3_lane_u32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3_lane_u64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3_lane_u8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3q_lane_f32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3q_lane_f64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3q_lane_p8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3q_lane_s16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3q_lane_s32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3q_lane_s64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3q_lane_s8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3q_lane_u16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3q_lane_u32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3q_lane_u64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld3q_lane_u8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4_lane_f32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4_lane_f64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4_lane_p8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4_lane_s16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4_lane_s32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4_lane_s64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4_lane_s8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4_lane_u16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4_lane_u32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4_lane_u64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4_lane_u8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4q_lane_f32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4q_lane_f64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4q_lane_p8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4q_lane_s16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4q_lane_s32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4q_lane_s64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4q_lane_s8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4q_lane_u16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4q_lane_u32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4q_lane_u64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vld4q_lane_u8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2_lane_f32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2_lane_f64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2_lane_p8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2_lane_s16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2_lane_s32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2_lane_s64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2_lane_s8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2_lane_u16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2_lane_u32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2_lane_u64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2_lane_u8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2q_lane_f32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2q_lane_f64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2q_lane_p8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2q_lane_s16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2q_lane_s32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2q_lane_s64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2q_lane_s8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2q_lane_u16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2q_lane_u32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2q_lane_u64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst2q_lane_u8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3_lane_f32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3_lane_f64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3_lane_p8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3_lane_s16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3_lane_s32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3_lane_s64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3_lane_s8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3_lane_u16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3_lane_u32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3_lane_u64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3_lane_u8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3q_lane_f32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3q_lane_f64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3q_lane_p8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3q_lane_s16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3q_lane_s32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3q_lane_s64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3q_lane_s8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3q_lane_u16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3q_lane_u32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3q_lane_u64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst3q_lane_u8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4_lane_f32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4_lane_f64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4_lane_p8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4_lane_s16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4_lane_s32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4_lane_s64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4_lane_s8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4_lane_u16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4_lane_u32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4_lane_u64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4_lane_u8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4q_lane_f32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4q_lane_f64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4q_lane_p8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4q_lane_s16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4q_lane_s32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4q_lane_s64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4q_lane_s8_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4q_lane_u16_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4q_lane_u32_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4q_lane_u64_indices_1.c:
New test.
        * gcc.target/aarch64/advsimd-intrinsics/vst4q_lane_u8_indices_1.c:
New test.