[compiler-rt] [compiler-rt][tests] Disable a test case unsupported on AArch64 (PR #117628)

[Paul Osmialowski via llvm-commits]

pawosm-arm wrote:

> Do you have more details about why this is unsupported? Is it due to i128 atomics and constants? Could just TEST_16 be disabled? I tried to run it locally but I don't think this test ran.

It doesn't surprise me, I'm using a very specific set of flags for compiler-rt, that make it truly contain atomic (needed for Flang OpenMP experiments with atomics):

```
    -DCOMPILER_RT_DEFAULT_TARGET_ARCH=AArch64
    -DCOMPILER_RT_BUILD_SANITIZERS=OFF
    -DCOMPILER_RT_BUILD_LIBFUZZER=ON
    -DCOMPILER_RT_BUILD_ORC=OFF
    -DCOMPILER_RT_USE_LIBCXX=ON
    -DCOMPILER_RT_BUILD_BUILTINS=ON
    -DCOMPILER_RT_USE_BUILTINS_LIBRARY=ON
    -DCOMPILER_RT_EXCLUDE_ATOMIC_BUILTIN=OFF
    -DCOMPILER_RT_BUILD_STANDALONE_LIBATOMIC=OFF
    -DCOMPILER_RT_USE_ATOMIC_LIBRARY=ON
    -DCOMPILER_RT_USE_LLVM_UNWINDER=OFF
```
Building it whith `-DCOMPILER_RT_USE_BUILTINS_LIBRARY=ON` is particularly tricky, it requires bootstrap compiler-rt built with `-DCOMPILER_RT_BUILD_BUILTINS=ON`.


https://github.com/llvm/llvm-project/pull/117628