remove unnecessary named exports check

Author: yyx990803

lib/loader.js

@@ -362,13 +362,6 @@ module.exports = function (content) {
     // add filename in dev
     output +=
       'Component.options.__file = ' + JSON.stringify(shortFilePath) + '\n'
-    // check named exports
-    output +=
-      'if (Component.esModule && Object.keys(Component.esModule).some(function (key) {' +
-      '  return key !== "default" && key.substr(0, 2) !== "__"' +
-      '})) {' +
-      '  console.error("named exports are not supported in *.vue files.")' +
-      '}\n'
   }
 
   // add requires for customBlocks