add computed property names support

lib/6to5/transformers/computed-property-names.js

@@ -0,0 +1,32 @@
+var util = require("../util");
+var _    = require("lodash");
+
+exports.ObjectExpression = function (node) {
+  var hasComputed = false;
+  var computed = [];
+
+  node.properties = node.properties.filter(function (prop) {
+    if (prop.computed) {
+      hasComputed = true;
+      computed.unshift(prop);
+      return false;
+    } else {
+      return true;
+    }
+  });
+
+  if (!hasComputed) return;
+
+  var container = util.template("function-return-obj", {
+    OBJECT: node
+  });
+
+  _.each(computed, function (prop) {
+    container.callee.body.body.unshift(util.template("obj-key-set", {
+      KEY: prop.key,
+      VALUE: prop.value
+    }, true));
+  });
+
+  return container;
+};