[clang] [libc] [llvm] [AMDGPU] Implement variadic functions by IR lowering (PR #93362)

[Joseph Huber via llvm-commits]

jhuber6 wrote:

> An offline suggestion from Pierre is that this should early-exit if there are no variadic functions in the module. That's a good thing, I'd like to consider it another of the increase-complexity-for-decreased-compile-time to implement after something has landed.

I thought any use of varargs would introduce LLVM intrinsics. Shouldn't it be trivial to look if any of those exist in the module?

https://github.com/llvm/llvm-project/pull/93362