[asveikau]

> It's not immediately clear to me why an LLVM implementation of the C++ standard library would be desirable while an implementation of the C standard library would be undesirable.

Worth noting the c++ standard library has had a lot of changes in recent years. libc has been hugely more stable in the same timeframe. (Notably there was C11, but the changes since C99 are not nearly what has been going on in c++ land.) The odds that whatever libc you already have is good enough are very high.