Set up rewriting triggers

src/parsing/preparser.h

Index: src/parsing/preparser.h
diff --git a/src/parsing/preparser.h b/src/parsing/preparser.h
index a0c59310628ac5b8a2e9bab6ed882e8e910dcd76..66a55cef078c294a014785332b990ff3682b8a07 100644
--- a/src/parsing/preparser.h
+++ b/src/parsing/preparser.h
@@ -938,13 +938,12 @@ class PreParserTraits {
   void SetFunctionNameFromPropertyName(PreParserExpression,
                                        PreParserIdentifier) {}
 
-  inline PreParserExpression RewriteExpression(PreParserExpression expr) {
-    return expr;
-  }
+  inline PreParserExpression RewriteExpression(
+      PreParserExpression expr, const ExpressionClassifier* classifier,
+      bool* ok);
   inline PreParserExpression RewriteObjectLiteralProperty(
-      PreParserExpression property) {
-    return property;
-  }
+      PreParserExpression property, const ExpressionClassifier* classifier,
+      bool* ok);
 
  private:
   PreParser* pre_parser_;
@@ -1127,6 +1126,22 @@ PreParserExpression PreParserTraits::ParseDoExpression(bool* ok) {
 }
 
 
+PreParserExpression PreParserTraits::RewriteExpression(
+    PreParserExpression expr, const ExpressionClassifier* classifier,
+    bool* ok) {
+  pre_parser_->ValidateExpression(classifier, ok);
+  return expr;
+}
+
+
+PreParserExpression PreParserTraits::RewriteObjectLiteralProperty(
+    PreParserExpression property, const ExpressionClassifier* classifier,
+    bool* ok) {
+  pre_parser_->ValidateExpression(classifier, ok);
+  return property;
+}
+
+
 PreParserStatementList PreParser::ParseEagerFunctionBody(
     PreParserIdentifier function_name, int pos,
     const PreParserFormalParameters& parameters, FunctionKind kind,