[libc-commits] [libc] [libc] Set default visibility for LLVM functions (PR #116686)

[Nick Desaulniers via libc-commits]

nickdesaulniers wrote:

> see for example: https://cs.opensource.google/fuchsia/fuchsia/+/main:zircon/system/ulib/c/BUILD.gn;l=184;drc=4cd8bba05cb37d30da9eb365b369ed0a0bb43267.

Right, that's exactly what bionic would need to do, too, without this PR. Once this PR lands, Bionic (and zircon, I suspect) no longer need to set `LLVM_LIBC_FUNCTION_ATTR` to default vis.

> That's why we provide the LLVM_LIBC_FUNCTION_ATTR macro

If that's the only downstream use case...and this PR fixes that use case...

> I cannot think of a reason why we'd ever want to expose the internal symbols

💯 hence #74881. 

https://github.com/llvm/llvm-project/pull/116686