add test case

Author: xurui1995

test/mlir/test/gc/Transforms/DecomposeAggregatedOps.mlir

@@ -0,0 +1,11 @@
+// RUN: gc-opt %s -decompose-aggregated-ops | FileCheck %s
+
+// CHECK-LABEL: softmax
+func.func @softmax(%arg0: tensor<2x2x2x2xf32>) -> tensor<2x2x2x2xf32> {
+  %0 = tensor.empty() : tensor<2x2x2x2xf32>
+  // CHECK-NOT: linalg.softmax
+  // CHECK-COUNT-4: linalg.generic
+  %1 = linalg.softmax dimension(3)
+    ins(%arg0 : tensor<2x2x2x2xf32>) outs(%0 : tensor<2x2x2x2xf32>) -> tensor<2x2x2x2xf32>
+  return %1 : tensor<2x2x2x2xf32>
+}