[derive] Use fallback types for big endian types on aarch64

Update src/impls.rs

Co-authored-by: Joshua Liebow-Feeser <[email protected]>

.github/workflows/ci.yml

@@ -240,6 +240,16 @@ jobs:
           - target: "wasm32-wasi"
             event_name: "pull_request"
 
+        include:
+          # big endian types should use fallback types till when
+          # Neon intrinsic are fixed 
+          # https://github.com/rust-lang/stdarch/issues/1484
+          # https://github.com/google/zerocopy/pull/1786
+          - toolchain: "nightly"
+            target: "aarch64_be-unknown-linux-gnu"
+            features: "--all-features"
+            crate: "zerocopy"
+
     name: Build & Test (${{ matrix.crate }} / ${{ matrix.toolchain }} / ${{ matrix.features }} / ${{ matrix.target }})
 
     steps:
@@ -575,6 +585,14 @@ jobs:
           # `roll-pinned-toolchain-versions.yml`.
           kani-version: 0.55.0
 
+  check_be_aarch64:
+    runs-on: ubuntu-latest
+    name: Check big endian for aarch64 target
+    steps:
+      - uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938 # v4.2.0
+      - name: Check big endian for aarch64 target
+        run: ./cargo.sh +nightly build --target=aarch64_be-unknown-linux-gnu -Zbuild-std --features simd
+
   check_fmt:
     runs-on: ubuntu-latest
     name: Check Rust formatting

src/impls.rs

@@ -934,7 +934,9 @@ mod simd {
         );
         #[cfg(zerocopy_aarch64_simd)]
         simd_arch_mod!(
-            #[cfg(target_arch = "aarch64")]
+            // NOTE(https://github.com/rust-lang/stdarch/issues/1484): NEON intrinsics are currently
+            // broken on big-endian platforms.
+            #[cfg(all(target_arch = "aarch64", target_endian = "little"))]
             aarch64, aarch64, float32x2_t, float32x4_t, float64x1_t, float64x2_t, int8x8_t, int8x8x2_t,
             int8x8x3_t, int8x8x4_t, int8x16_t, int8x16x2_t, int8x16x3_t, int8x16x4_t, int16x4_t,
             int16x8_t, int32x2_t, int32x4_t, int64x1_t, int64x2_t, poly8x8_t, poly8x8x2_t, poly8x8x3_t,