add uid scope kind

lib/6to5/transformation/file.js

@@ -460,7 +460,7 @@ File.prototype.generateUid = function (name, scope) {
 File.prototype.generateUidIdentifier = function (name, scope) {
   scope = scope || this.scope;
   var id = t.identifier(this.generateUid(name, scope));
-  scope.addBindingToFunctionScope(id);
+  scope.addBindingToFunctionScope(id, "uid");
   return id;
 };
 

lib/6to5/traversal/scope.js

@@ -246,7 +246,7 @@ var programReferenceVisitor = {
   enter: function (node, parent, scope, state) {
     if (t.isReferencedIdentifier(node, parent) && !scope.hasReference(node.name)) {
       state.register(node, true);
-    } else if (t.isLabelStatemented(node)) {
+    } else if (t.isLabeledStatement(node)) {
       state.register(node.label, true);
     }
   }
@@ -283,7 +283,8 @@ Scope.prototype.crawl = function () {
       "const": object(),
       param:   object(),
       "var":   object(),
-      "let":   object()
+      "let":   object(),
+      uid:     object()
     },
 
     references: object(),