[parser] early error when declaration Pattern missing Initializer

test/message/const-decl-no-init.out

Index: test/message/const-decl-no-init.out
diff --git a/test/message/import-reserved-word.out b/test/message/const-decl-no-init.out
similarity index 53%
copy from test/message/import-reserved-word.out
copy to test/message/const-decl-no-init.out
index 5b990e9e590aa6088f1fe5a058eac16f88a238f0..42f1219b3c96e76a52f9736ded98a7f8456a523d 100644
--- a/test/message/import-reserved-word.out
+++ b/test/message/const-decl-no-init.out
@@ -1,7 +1,7 @@
 # Copyright 2015 the V8 project authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
-*%(basename)s:7: SyntaxError: Unexpected reserved word
-import { import } from "mod";
-         ^^^^^^
-SyntaxError: Unexpected reserved word
+*%(basename)s:6: SyntaxError: Missing initializer in const declaration
+const a;
+      ^
+SyntaxError: Missing initializer in const declaration