Add aarch64_be CI run

Author: sayantn

ci/docker/aarch64_be-unknown-linux-gnu/Dockerfile

@@ -28,3 +28,5 @@ ENV CARGO_TARGET_AARCH64_BE_UNKNOWN_LINUX_GNU_LINKER="${AARCH64_BE_TOOLCHAIN}/bi
 ENV CARGO_TARGET_AARCH64_BE_UNKNOWN_LINUX_GNU_RUNNER="qemu-aarch64_be -cpu max -L ${AARCH64_BE_LIBC}"
 ENV OBJDUMP="${AARCH64_BE_TOOLCHAIN}/bin/bin/aarch64-none-linux-gnu-objdump"
 ENV STDARCH_TEST_SKIP_FEATURE=tme
+
+ENV CARGO_UNSTABLE_BUILD_STD=std

crates/simd-test-macro/src/lib.rs

@@ -58,7 +58,7 @@ pub fn simd_test(
     {
         "i686" | "x86_64" | "i586" => "is_x86_feature_detected",
         "arm" | "armv7" => "is_arm_feature_detected",
-        "aarch64" | "arm64ec" => "is_aarch64_feature_detected",
+        "aarch64" | "arm64ec" | "aarch64_be" => "is_aarch64_feature_detected",
         maybe_riscv if maybe_riscv.starts_with("riscv") => "is_riscv_feature_detected",
         "powerpc" | "powerpcle" => "is_powerpc_feature_detected",
         "powerpc64" | "powerpc64le" => "is_powerpc64_feature_detected",