Re-introduce ImportDeclaration to the parser

test/message/import-as-redeclaration.out

Index: test/message/import-as-redeclaration.out
diff --git a/test/message/import-as-redeclaration.out b/test/message/import-as-redeclaration.out
new file mode 100644
index 0000000000000000000000000000000000000000..51c4c032dc889dbce9c2a3ec8673f2f89f3c26c6
--- /dev/null
+++ b/test/message/import-as-redeclaration.out
@@ -0,0 +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:8: SyntaxError: Identifier 'foo' has already been declared
+import { bar as foo } from "mod";
+                ^^^
+SyntaxError: Identifier 'foo' has already been declared