Clone tokens when cloning ASTs for constants

editor/tools/plugins/com.google.dart.engine_test/src/com/google/dart/engine/utilities/ast/AstClonerTest.java

Index: editor/tools/plugins/com.google.dart.engine_test/src/com/google/dart/engine/utilities/ast/AstClonerTest.java
diff --git a/editor/tools/plugins/com.google.dart.engine_test/src/com/google/dart/engine/utilities/ast/AstClonerTest.java b/editor/tools/plugins/com.google.dart.engine_test/src/com/google/dart/engine/utilities/ast/AstClonerTest.java
index f5ac447759cc1c4c2545c5d306707bc462dc70e1..ce151c50da16c13fc296756a5453401f51b20fd1 100644
--- a/editor/tools/plugins/com.google.dart.engine_test/src/com/google/dart/engine/utilities/ast/AstClonerTest.java
+++ b/editor/tools/plugins/com.google.dart.engine_test/src/com/google/dart/engine/utilities/ast/AstClonerTest.java
@@ -76,6 +76,10 @@ public class AstClonerTest extends EngineTestCase {
     assertClone(assignmentExpression(identifier("a"), TokenType.EQ, identifier("b")));
   }
 
+  public void test_visitAwaitExpression() {
+    assertClone(awaitExpression(identifier("a")));
+  }
+
   public void test_visitBinaryExpression() {
     assertClone(binaryExpression(identifier("a"), TokenType.PLUS, identifier("b")));
   }
@@ -1521,6 +1525,10 @@ public class AstClonerTest extends EngineTestCase {
     assertClone(withClause(typeName("A")));
   }
 
+  public void test_visitYieldStatement() {
+    assertClone(yieldStatement(identifier("A")));
+  }
+
   /**
    * Assert that an {@code AstCloner} will produce the expected ASt structure when visiting the
    * given node.