LLVM does not properly handle debug info for f16 on the aarch64-windows
target, causing "fatal error: unknown codeview register H1". The
previous workaround checked only for f16 but was still vulnerable if a
type was a byval struct or tuple which had an f16 field in it.

Now I have filed an upstream issue (see
https://github.com/llvm/llvm-project/issues/56484) and broadened the
workaround to always skip debug values for this target.