[clang] [lld] [llvm] [LTO][LLD] Prevent invalid LTO libfunc transforms (PR #164916)

[Daniel Thornburgh via llvm-commits]

mysterymath wrote:

Posted https://github.com/llvm/llvm-project/pull/189502 for the Expensive Checks failure; this uncovered a latent issue in SimplifyLibCalls.

https://github.com/llvm/llvm-project/pull/164916