[turbofan] Implement sharing of context-independent code.

src/hydrogen-instructions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HYDROGEN_INSTRUCTIONS_H_
 #define V8_HYDROGEN_INSTRUCTIONS_H_
 
 #include <cstring>
 #include <iosfwd>
 
@@ skipping 5962 matching lines @@
 
   static HObjectAccess ForCodeOffset() {
     return HObjectAccess(kInobject, SharedFunctionInfo::kCodeOffset);
   }
 
   static HObjectAccess ForOptimizedCodeMap() {
     return HObjectAccess(kInobject,
                          SharedFunctionInfo::kOptimizedCodeMapOffset);
   }
 
+  static HObjectAccess ForOptimizedCodeMapSharedCode() {
+    return HObjectAccess(kInobject, FixedArray::OffsetOfElementAt(
+                                        SharedFunctionInfo::kSharedCodeIndex));
+  }
+
   static HObjectAccess ForFunctionContextPointer() {
     return HObjectAccess(kInobject, JSFunction::kContextOffset);
   }
 
   static HObjectAccess ForMap() {
     return HObjectAccess(kMaps, JSObject::kMapOffset);
   }
 
   static HObjectAccess ForPrototype() {
     return HObjectAccess(kMaps, Map::kPrototypeOffset);
@@ skipping 1904 matching lines @@
 };
 
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_