[compiler-rt] [libc] [compiler-rt][builtins] add libc-backed double/float-to-int builtins (PR #207543)

[Jeff Bailey via llvm-commits]

https://github.com/kaladron commented:

Just a quick fly-by note of the headers in the compiler-rt directory (unless they have a different standard than the rest of LLVM, in which case please ignore)

https://github.com/llvm/llvm-project/pull/207543