[clang] [llvm] [mlir] [MLIR] Add f8E4M3 IEEE 754 type (PR #97118)

[Maksim Levental via cfe-commits]

makslevental wrote:

Hey @apivovarov I just wanted to say my bad for not getting to this yet - I'm buried at work but I haven't forgotten. If it's hipri I can find someone else to review. Otherwise ~couple of days I think and I'll be clear to review.

https://github.com/llvm/llvm-project/pull/97118