Revert "Merge more Kernel infrastructure from kernel_sdk SDK fork."

runtime/lib/developer.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.
 
 import 'dart:isolate';
-import 'dart:_internal';
 
 @patch bool debugger({bool when: true,
                      String message}) native "Developer_debugger";
 
 @patch Object inspect(Object object) native "Developer_inspect";
 
 @patch void log(String message,
                 {DateTime time,
                  int sequenceNumber,
                  int level: 0,
@@ skipping 125 matching lines @@
     sb.write('"result":');
   }
   sb.write('${response._toString()},');
   if (id is String) {
     sb.write('"id":"$id"}');
   } else {
     sb.write('"id":$id}');
   }
   replyPort.send(sb.toString());
 }