[clang] [llvm] Triple::normalize: Use none as OS for XX-none-ABI (PR #89638)

[David Spickett via cfe-commits]

DavidSpickett wrote:

@wzssyqa thanks for working with us on this. Bare metal is always a wild card but I think in the end we'll all have cleaner builds because of these changes.

https://github.com/llvm/llvm-project/pull/89638