[libc-commits] [libc] [libc] Remove obsolete LIBC_HAS_BUILTIN macro (PR #86554)

[Nick Desaulniers via libc-commits]

nickdesaulniers wrote:

> Okay I vaguely recall one niche use-case that this will break. Currently I build the RPC loader / server utilities in the main LLVM build similar to how we build `libc-hdrgen`.

This is code in utils/gpu/ ?

https://github.com/llvm/llvm-project/pull/86554