[llvm] [clang] [SystemZ] Properly support 16 byte atomic int/fp types and ops. (PR #73134)

[Jonas Paulsson via cfe-commits]

JonPsson1 wrote:

Not sure about GCC here, as far as I can see, it is returning true for both of the 8-byte aligned cases in gnu-atomic_is_lock_free-i128-8Al.c, also now that the alignment is actually 8...

GCC is returning true for all in gnu-atomic_is_lock_free-i128-16Al.c, except for except for emitting a call to __c11_atomic_is_lock_free.

https://github.com/llvm/llvm-project/pull/73134