Don't depend on V8 when creating the SDK.

dart/utils/compiler/compiler.gyp

 # Copyright (c) 2012, 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.
 
 {
   'variables': {
     'dart_dir': '../..',
   },
   'targets': [
     {
       'target_name': 'dart2js',
       'type': 'none',
       'dependencies': [
         '../../runtime/dart-runtime.gyp:dart',
-        '../../third_party/v8/src/d8.gyp:d8',
       ],
       'actions': [
         {
           'action_name': 'build_dart2js',
           'inputs': [
             '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)dart<(EXECUTABLE_SUFFIX)',
             'build_helper.dart',
           ],
           'outputs': [
             '<(PRODUCT_DIR)/dart2js',
@@ skipping 42 matching lines @@
             # for dart2js compiler engineers.  However, we install the
             # snapshot in the proper location when building the SDK.
             '--script_snapshot=<(PRODUCT_DIR)/dart2js.snapshot',
             '../../lib/compiler/implementation/dart2js.dart',
           ],
         },
       ],
     },
   ],
 }