Minimize differences between ia32 and x64 sources to facilitate maintenance.

runtime/vm/flow_graph_compiler_x64.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_X64_H_
 #define VM_FLOW_GRAPH_COMPILER_X64_H_
 
 #ifndef VM_FLOW_GRAPH_COMPILER_H_
 #error Include flow_graph_compiler.h instead of flow_graph_compiler_x64.h.
 #endif
 
 namespace dart {
 
 class Code;
 class DeoptimizationStub;
-class ExceptionHandlerList;
 template <typename T> class GrowableArray;
 class ParsedFunction;
 
 class FlowGraphCompiler : public ValueObject {
  private:
   struct BlockInfo : public ZoneAllocated {
    public:
     BlockInfo() : label() { }
     Label label;
   };
@@ skipping 40 matching lines @@
 
   // Returns 'true' if code generation for this function is complete, i.e.,
   // no fall-through to regular code is needed.
   bool TryIntrinsify();
 
   void GenerateCallRuntime(intptr_t cid,
                            intptr_t token_pos,
                            intptr_t try_index,
                            const RuntimeEntry& entry);
 
-  // Infrastructure copied from class CodeGenerator.
   void GenerateCall(intptr_t token_pos,
                     intptr_t try_index,
                     const ExternalLabel* label,
                     PcDescriptors::Kind kind);
 
   void GenerateAssertAssignable(intptr_t cid,
                                 intptr_t token_pos,
                                 intptr_t try_index,
                                 const AbstractType& dst_type,
                                 const String& dst_name);
@@ skipping 227 matching lines @@
   const DeoptReasonId reason_;
   GrowableArray<Register> registers_;
   Label entry_label_;
 
   DISALLOW_COPY_AND_ASSIGN(DeoptimizationStub);
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_COMPILER_X64_H_