At the moment the below header tests fail with the multilib error in LLVM Embedded Toolchain for Arm because there is no corresponding aarch64 big endian library variant exist. Specifying --sysroot to its own testing directory clang/test/Headers/Inputs (which does not have any dependency library) prevents these header tests from being located in standard library directories.
- clang/test/Headers/arm-neon-header.c
- clang/test/Headers/arm-fp16-header.c