[llvm] fix a assert on the PR 125883 (PR #135056)

[Jakub Kuderski via llvm-commits]

https://github.com/kuhar commented:

This doesn't fix the downstream crash I reported in https://github.com/llvm/llvm-project/pull/125883#issuecomment-2787048206

https://github.com/llvm/llvm-project/pull/135056