[clang] [llvm] [mlir] [polly] [IR] Add alias scope domains with disjoint scopes (PR #218768)

[Bruno De Fraine via llvm-commits]

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brunodf-gf wrote:

The documentation of this function, in header "Cloning.h" says: "Be aware that the cloned scopes are still part of the original scope domain". With the change here for cloning disjoint-scope domains that is no longer true, so the description should be updated as part of your patch too.

https://github.com/llvm/llvm-project/pull/218768