[llvm] [Inliner] Check number of operands in AddReturnAttributes (PR #87093)

[Dmitrii Dolgov via llvm-commits]

erthalion wrote:

With help from @macdice we most likely found the reason behind https://github.com/llvm/llvm-project/issues/86162. PostgreSQL generates the module passed to the inliner, and it turns out one part of the generator copies function attributes, eventually applying `noudef` where it shouldn't be applied. Adding `verify` pass shows it early on, thanks for the advice!

Unless you folks think that the extra check proposed in this PR makes sense as a general defense measure, I'm going to close the PR and the issue.

https://github.com/llvm/llvm-project/pull/87093