[llvm] [GlobalOpt] Don't replace aliasee with alias that has weak linkage (PR #91483)

[Fangrui Song via llvm-commits]

MaskRay wrote:

How do we get `@f2 = linkonce_odr hidden alias void (), ptr @f1` in the first place?

`weak/linkonce` stopping the replace makes sense to me but `weak_odr/linkonce_odr` should not.

https://github.com/llvm/llvm-project/pull/91483