[clang] [Sema] Warning for _Float16 passed to format specifier '%f' (PR #74439)

[via cfe-commits]

apple-fcloutier wrote:

[N2844](https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2844.pdf), as linked by OP, references the removed language that you are looking for.

As Aaron said, it doesn't matter if clang never claimed conformance/never implemented default argument promotion for these types in the first place.

https://github.com/llvm/llvm-project/pull/74439