[llvm-branch-commits] [libcxx] XFAIL some tests for LLVM libc (PR #193644)

[Aiden Grossman via llvm-branch-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/193644

Mark the tests that are currently failing on LLVM libc with the new
CMake cache as XFAIL so that we can get CI stood up as soon as possible.