add VirtualPropertyExpression and SpreadProperty to ast-types

lib/6to5/patch.js

@@ -3,6 +3,7 @@ var _ = require("lodash");
 
 var types = require("ast-types");
 var def   = types.Type.def;
+var or    = types.Type.or;
 
 // Program wrapper
 def("File")
@@ -16,12 +17,26 @@ def("ParenthesizedExpression")
   .build("expression")
   .field("expression", def("Expression"));
 
-// Same as ImportNamespaceSpecifier but `id` is `name`
+// Acorn - Same as ImportNamespaceSpecifier but `id` is `name`
 def("ImportBatchSpecifier")
   .bases("Specifier")
   .build("name")
   .field("name", def("Identifier"));
 
+// Abstract references
+def("VirtualPropertyExpression")
+  .bases("Expression")
+  .build("object", "property")
+  .field("object", def("Expression"))
+  .field("property", or(def("Identifier"), def("Expression")));
+
+// Spread properties
+def("SpreadProperty")
+  .bases("Property")
+  .build("argument")
+  .field("argument", def("Expression"));
+
+
 types.finalize();
 
 var estraverse = require("estraverse");