First step in reducing the size of PC descriptors.

runtime/vm/flow_graph_compiler.h

 // 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.
 
 #ifndef VM_FLOW_GRAPH_COMPILER_H_
 #define VM_FLOW_GRAPH_COMPILER_H_
 
 #include "vm/allocation.h"
 #include "vm/assembler.h"
 #include "vm/code_descriptors.h"
@@ skipping 576 matching lines @@
   const Class& list_class_;
 
   ParallelMoveResolver parallel_move_resolver_;
 
   // Currently instructions generate deopt stubs internally by
   // calling AddDeoptStub.  To communicate deoptimization environment
   // that should be used when deoptimizing we store it in this variable.
   // In future AddDeoptStub should be moved out of the instruction template.
   Environment* pending_deoptimization_env_;
 
+  intptr_t entry_patch_pc_offset_;
+  intptr_t patch_code_pc_offset_;
+  intptr_t lazy_deopt_pc_offset_;
+
   DISALLOW_COPY_AND_ASSIGN(FlowGraphCompiler);
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_COMPILER_H_