[analyzer] fix NodeReplacer for AwaitExpression

pkg/analyzer/test/generated/utilities_test.dart

Index: pkg/analyzer/test/generated/utilities_test.dart
diff --git a/pkg/analyzer/test/generated/utilities_test.dart b/pkg/analyzer/test/generated/utilities_test.dart
index d13c79ea93d031ccae1cf4c0991402db8ccd4b12..3219e909531fd34cf752cb300c342c95c6a58ad0 100644
--- a/pkg/analyzer/test/generated/utilities_test.dart
+++ b/pkg/analyzer/test/generated/utilities_test.dart
@@ -1943,6 +1943,12 @@ class Getter_NodeReplacerTest_test_assignmentExpression_2
   Expression get(AssignmentExpression node) => node.leftHandSide;
 }
 
+class Getter_NodeReplacerTest_test_awaitExpression
+    implements NodeReplacerTest_Getter {
+  @override
+  Expression get(AwaitExpression node) => node.expression;
+}
+
 class Getter_NodeReplacerTest_test_binaryExpression
     implements NodeReplacerTest_Getter {
   @override
@@ -3284,6 +3290,11 @@ class NodeReplacerTest extends EngineTestCase {
         node, new Getter_NodeReplacerTest_test_assignmentExpression());
   }
 
+  void test_awaitExpression() {
+    var node = AstFactory.awaitExpression(AstFactory.identifier3("A"));
+    _assertReplace(node, new Getter_NodeReplacerTest_test_awaitExpression());
+  }
+
   void test_binaryExpression() {
     BinaryExpression node = AstFactory.binaryExpression(
         AstFactory.identifier3("l"), TokenType.PLUS,