[llvm] [ADT][APFloat] Make sure EBO is performed on APFloat (PR #111641)

[Matt Arsenault via llvm-commits]

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

LGTM but I think APFloatBase should just be removed. There are a few other cleanups I would like to do here too (like all of the semantics* queries are noise and we would be better off just making fltSemantics fields visible) 

https://github.com/llvm/llvm-project/pull/111641