[mlir] [llvm] [mlir][Interfaces] Add `SubsetOpInterface` and `SubsetExtractionOpInterface` (PR #70617)

[Nicolas Vasilache via llvm-commits]

================
@@ -9,12 +9,29 @@
 #include "mlir/Dialect/Linalg/Transforms/SubsetInsertionOpInterfaceImpl.h"
 
 #include "mlir/Dialect/Linalg/IR/Linalg.h"
-#include "mlir/Interfaces/SubsetInsertionOpInterface.h"
+#include "mlir/Interfaces/SubsetOpInterface.h"
 
 using namespace mlir;
 using namespace mlir::linalg;
 
 namespace {
+struct LinalgCopyOpSubsetOpInterface
+    : public SubsetOpInterface::ExternalModel<LinalgCopyOpSubsetOpInterface,
+                                              linalg::CopyOp> {
+  bool operatesOnEquivalentSubset(
----------------
nicolasvasilache wrote:

Can we add a comment here to explain?
I would have thought copy ops operate on equivalent subsets by construction.

https://github.com/llvm/llvm-project/pull/70617