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

src/parser.h

Index: src/parser.h
diff --git a/src/parser.h b/src/parser.h
index 4929bbb91e61378427b1763bc469edc7744040e2..c8fb5611fee2a01a478023bce34946b7e916c38e 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -909,10 +909,11 @@ class Parser : public ParserBase<ParserTraits> {
                                 ZoneList<const AstRawString*>* names,
                                 bool* ok);
   Block* ParseVariableDeclarations(VariableDeclarationContext var_context,
+                                   int* num_decl,
                                    ZoneList<const AstRawString*>* names,
                                    const AstRawString** out,
                                    Scanner::Location* first_initializer_loc,
-                                   bool* ok);
+                                   Scanner::Location* bindings_loc, bool* ok);
   Statement* ParseExpressionOrLabelledStatement(
       ZoneList<const AstRawString*>* labels, bool* ok);
   IfStatement* ParseIfStatement(ZoneList<const AstRawString*>* labels,