[llvm-branch-commits] [mlir] [mlir][Interfaces][NFC] Document that `RegionBranchTerminatorOpInterface` is mandatory (PR #174978)

[lonely eagle via llvm-branch-commits]

linuxlonelyeagle wrote:

I am thinking about whether this conclusion is correct: `If a TerminatorOp does not implement the RegionBranchTerminatorOpInterface, does that mean it has no successors?` If this conclusion is correct, I think it would be better to add it to the assumptions.

https://github.com/llvm/llvm-project/pull/174978