[compiler-rt] [builtins] Avoid using long double in FreeBSD standalone environment (PR #76175)

[Saleem Abdulrasool via llvm-commits]

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

Sure, this seems reasonable.  I still wonder if anyone is going to be imapcted by the missing type definitions, but if they are, we can deal with them then.

https://github.com/llvm/llvm-project/pull/76175