[clang] [llvm] [APFloat] Add support for f8E3M4 IEEE 754 type (PR #99698)

[Thorsten Schütt via llvm-commits]

tschuett wrote:

> @tschuett, Could you please help review this change?

I did. I gave you the float reviewer of the house.

https://github.com/llvm/llvm-project/pull/99698