[clang] [llvm] [APFloat] Add APFloat support for FP6 data types (PR #94735)

[Thomas Raoux via cfe-commits]

https://github.com/ThomasRaoux approved this pull request.

LGTM, please wait to confirm that everybody is happy with the naming before merging.

@krzysz00 was your comment meant to be a blocker?

https://github.com/llvm/llvm-project/pull/94735