[MLIR][XeGPU][Transform] add xegpu.set_desc_layout transform op (#165615)

Adds the first XeGPU transform op, `xegpu.set_desc_layout`, which attachs a `xegpu.layout` attribute to the descriptor that a `xegpu.create_nd_tdesc` op returns.

mlir/test/python/dialects/transform_xegpu_ext.py

@@ -0,0 +1,51 @@
+# RUN: %PYTHON %s | FileCheck %s
+
+from mlir.ir import *
+from mlir.dialects import transform
+from mlir.dialects.transform import xegpu
+from mlir.dialects.transform import structured
+
+
+def run(f):
+    with Context(), Location.unknown():
+        module = Module.create()
+        with InsertionPoint(module.body):
+            print("\nTEST:", f.__name__)
+            f()
+        print(module)
+    return f
+
+
+@run
+def setDescLayoutMinimal():
+    sequence = transform.SequenceOp(
+        transform.FailurePropagationMode.Propagate,
+        [],
+        transform.OperationType.get("xegpu.create_nd_tdesc"),
+    )
+    with InsertionPoint(sequence.body):
+        xegpu.SetDescLayoutOp(sequence.bodyTarget, sg_layout=[6, 4], sg_data=[32, 16])
+        transform.YieldOp()
+    # CHECK-LABEL: TEST: setDescLayoutMinimal
+    # CHECK: %0 = transform.xegpu.set_desc_layout %
+    # CHECK: sg_layout = [6, 4]
+    # CHECK: sg_data = [32, 16]
+
+
+@run
+def setDescLayoutInstData():
+    sequence = transform.SequenceOp(
+        transform.FailurePropagationMode.Propagate,
+        [],
+        transform.OperationType.get("xegpu.create_nd_tdesc"),
+    )
+    with InsertionPoint(sequence.body):
+        xegpu.SetDescLayoutOp(
+            sequence.bodyTarget, sg_layout=[6, 4], sg_data=[32, 16], inst_data=[8, 16]
+        )
+        transform.YieldOp()
+    # CHECK-LABEL: TEST: setDescLayoutInstData
+    # CHECK: %0 = transform.xegpu.set_desc_layout %
+    # CHECK: sg_layout = [6, 4]
+    # CHECK: sg_data = [32, 16]
+    # CHECK: inst_data = [8, 16]