[llvm] [TLI] Fix replace-with-veclib crash with invalid arguments (PR #77112)

[Pranav Kant via llvm-commits]

pranavk wrote:

Hmm, my internal bisect suggests that this commit seems to fail llvm/unittests/Analysis/ConstraintSystemTest.cpp 
Have you verified that it isn't regressing this after your commit?

https://github.com/llvm/llvm-project/pull/77112