fix js build

.gitignore

@@ -14,7 +14,7 @@
 *.o
 .*.c
 *.tmp.c
-
+vjs
 *.obj
 
 *.pdb

vlib/builtin/js/hashmap.v

@@ -0,0 +1,13 @@
+// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+module builtin
+
+/*
+TODO: Implement hashmap for js when hashmap for V is done.
+*/
+
+fn foo() {
+
+}