[llvm] [FuncComp] Compare MDNodes in cmpMetadata using cmpMDNode. (PR #128878)

[Florian Hahn via llvm-commits]

https://github.com/fhahn commented:

I updated the PR to restrict the types of metadata nodes allowed in metadata arguments (most important there's guaranteed that there are no cycles). This should allow all current uses, should we document the restrictions?

This should allow recursing in FunctionComperator in contexts where the metadata as function argument. 

https://github.com/llvm/llvm-project/pull/128878