[parser] report better errors for multiple ForBindings in ForIn/Of loops

src/preparser.h

Index: src/preparser.h
diff --git a/src/preparser.h b/src/preparser.h
index 35b65853b3f553560df54e873043ea26efc2d128..1ade9a7e6ff77becf07be9fb2f7b57a49cb224f4 100644
--- a/src/preparser.h
+++ b/src/preparser.h
@@ -1587,6 +1587,7 @@ class PreParser : public ParserBase<PreParserTraits> {
   Statement ParseVariableDeclarations(VariableDeclarationContext var_context,
                                       int* num_decl,
                                       Scanner::Location* first_initializer_loc,
+                                      Scanner::Location* bindings_loc,
                                       bool* ok);
   Statement ParseExpressionOrLabelledStatement(bool* ok);
   Statement ParseIfStatement(bool* ok);