[mlir][transform][structured][python] Allow str arg in match_op_names.

[ingomueller-net]

Summary

Allow the names argument in MatchOp.match_op_names to be of type
str in addition to Sequence[str]. In this case, the argument is
treated as a list with one name, i.e., it is possible to write
MatchOp.match_op_names(..., "test.dummy") instead of
MatchOp.match_op_names(..., ["test.dummy"]).

mlir/python/mlir/dialects/_structured_transform_ops_ext.py

 class MatchOp:
     """Specialization for MatchOp class."""
 
     @overload
     @classmethod
     def match_op_names(
         cls,
         target: Union[Operation, Value],
-        names: Sequence[str],
+        names: Union[str, Sequence[str]],
         *,
         loc=None,
         ip=None,
     ):
        ...
 
     @overload
     @classmethod
     def match_op_names(
         cls,
         result_type: Type,
         target: Union[Operation, Value],
-        names: Sequence[str],
+        names: Union[str, Sequence[str]],
         *,
         loc=None,
         ip=None,
     ):
        ...
 
     @classmethod
     def match_op_names(
         cls,
         result_type_or_target: Union[Type, Operation, Value],
-        target_or_names: Union[Operation, Value,  Sequence[str]],
-        names_or_none: Optional[Sequence[str]] = None,
+        target_or_names: Union[Operation, Value, Sequence[str], str],
+        names_or_none: Optional[Union[Sequence[str], str]] = None,
         *,
         loc=None,
         ip=None,
     ):
         if isinstance(result_type_or_target, Type):
            result_type = result_type_or_target
            target = target_or_names
            names = names_or_none
         else:
            result_type = transform.AnyOpType.get()
            target = result_type_or_target
            names = target_or_names
 
+        if isinstance(names, str):
+           names = [names]
+
         return cls(
             result_type,
             _get_op_result_or_value(target),
             ops=ArrayAttr.get(list(map(lambda s: StringAttr.get(s), names))),
             loc=loc,
             ip=ip,
         )
 

mlir/test/python/dialects/transform_structured_ext.py

with InsertionPoint(sequence.body):
         transform.YieldOp()
     # CHECK-LABEL: TEST: testInterchange
     # CHECK: transform.sequence
     # CHECK: transform.structured.interchange
     # CHECK: iterator_interchange = [1, 0]
 
 
 @run
-def testMatchOpNames():
+def testMatchOpNamesString():
+    sequence = transform.SequenceOp(
+        transform.FailurePropagationMode.PROPAGATE, [], transform.AnyOpType.get()
+    )
+    with InsertionPoint(sequence.body):
+        structured.MatchOp.match_op_names(sequence.bodyTarget, "test.dummy")
+        transform.YieldOp()
+    # CHECK-LABEL: TEST: testMatchOpNamesString
+    # CHECK: transform.structured.match ops
+    # CHECK-SAME: ["test.dummy"]
+    # CHECK-SAME: (!transform.any_op) -> !transform.any_op
+
+
+@run
+def testMatchOpNamesList():
     sequence = transform.SequenceOp(
         transform.FailurePropagationMode.PROPAGATE, [], transform.AnyOpType.get()
     )
     with InsertionPoint(sequence.body):
         structured.MatchOp.match_op_names(sequence.bodyTarget, ["test.dummy"])
         transform.YieldOp()
-    # CHECK-LABEL: TEST: testMatchOpNames
+    # CHECK-LABEL: TEST: testMatchOpNamesList
     # CHECK: transform.structured.match ops
     # CHECK-SAME: ["test.dummy"]
     # CHECK-SAME: (!transform.any_op) -> !transform.any_op
 
 
 @run
 def testMatchOpNamesTyped():
     sequence = transform.SequenceOp(