Reinstate libc++ patches now that the lldb formatter has been updated.

"[libc++] Fix <atomic> failures on GCC"
"[libc++] Change memory_order to an enum class"
"[libc++] decoupling Freestanding atomic<T> from libatomic.a"

llvm-svn: 355427
GitOrigin-RevId: 6de760ac4e80d6fa26b02e5aa63f8493b3fca2a8
6 files changed