Fix internal NSM helper to use a Dart Symbol

tool/input_sdk/private/operations.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// This library defines runtime operations on objects used by the code
 /// generator.
 part of dart._runtime;
 
 _canonicalFieldName(obj, name, args, displayName) => JS('', '''(() => {
   $name = $canonicalMember($obj, $name);
@@ skipping 56 matching lines @@
   if (names.length == 0) return false;
   for (var name of names) {
     if (!($hasOwnProperty.call($type.named, name))) {
       return false;
     }
     if (!$instanceOfOrNull(opts[name], $type.named[name])) return false;
   }
   return true;
 })()''');
 
+_dartSymbol(name) => JS('', '''
+  $const_($Symbol.new($name.toString()))
+''');
 
 throwNoSuchMethod(obj, name, pArgs, nArgs, extras) => JS('', '''(() => {
-  $throw_(new $NoSuchMethodError($obj, $name, $pArgs, $nArgs, $extras));
+  $throw_(new $NoSuchMethodError($obj, $_dartSymbol($name), $pArgs, $nArgs, $extras));
 })()''');
 
 throwNoSuchMethodFunc(obj, name, pArgs, opt_func) => JS('', '''(() => {
   if ($obj === void 0) $obj = $opt_func;
   $throwNoSuchMethod($obj, $name, $pArgs);
 })()''');
 
 checkAndCall(f, ftype, obj, args, name) => JS('', '''(() => {
   let originalFunction = $f;
   if (!($f instanceof Function)) {
@@ skipping 332 matching lines @@
     constructor(dartIterator) {
       this.dartIterator = dartIterator;
     }
     next() {
       let i = this.dartIterator;
       let done = !i.moveNext();
       return { done: done, value: done ? void 0 : i.current };
     }
   }
 ''');