VM: Move branch optimizations into a separate file.

runtime/vm/vm_sources.gypi

 # Copyright (c) 2013, 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 file contains all sources (vm and tests) for the dart virtual machine.
 # Unit test files need to have a '_test' suffix appended to the name.
 {
   'sources': [
     'allocation.cc',
     'allocation.h',
@@ skipping 45 matching lines @@
     'bitmap.cc',
     'bitmap.h',
     'bitmap_test.cc',
     'block_scheduler.cc',
     'block_scheduler.h',
     'boolfield.h',
     'boolfield_test.cc',
     'bootstrap.h',
     'bootstrap_natives.cc',
     'bootstrap_natives.h',
+    'branch_optimizer.cc',
+    'branch_optimizer.h',
     'cha.cc',
     'cha.h',
     'cha_test.cc',
     'class_finalizer.cc',
     'class_finalizer.h',
     'class_finalizer_test.cc',
     'class_table.cc',
     'class_table.h',
     'code_descriptors.cc',
     'code_descriptors.h',
@@ skipping 433 matching lines @@
     'vtune.h',
     'weak_code.cc',
     'weak_code.h',
     'weak_table.cc',
     'weak_table.h',
     'zone.cc',
     'zone.h',
     'zone_test.cc',
   ],
 }