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

[Alexander Pivovarov via cfe-commits]

apivovarov wrote:

> If this is a new float type, could you please split out the apfloat changes in separate PR.

Sure - [PR-97179](https://github.com/llvm/llvm-project/pull/97179) Add f8E4M3 IEEE 754 type to llvm

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