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

[lonely eagle via llvm-branch-commits]

linuxlonelyeagle wrote:

> Yes, that's correct. I added a note to the `RegionBranchTerminatorOpInterface` documentation.

Thanks.

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