Add pointer cache field to external string for access in generated code.

src/code-stubs.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 776 matching lines @@
   // Generates the fast case code. On the fallthrough path |result|
   // register contains the result.
   void GenerateFast(MacroAssembler* masm);
 
   // Generates the slow case code. Must not be naturally
   // reachable. Expected to be put after a ret instruction (e.g., in
   // deferred code). Always jumps back to the fast case.
   void GenerateSlow(MacroAssembler* masm,
                     const RuntimeCallHelper& call_helper);
 
+  // Generates the code for handling different string types and loading the
+  // result character.  We expect |index| to be not smi-tagged.

[Lasse Reichstein, 2011/11/17 13:40:18]

"not smi-tagged" -> "untagged".

+  static void GenerateCharLoad(MacroAssembler* masm,
+                               Factory* factory,
+                               Register string,
+                               Register index,
+                               Register result,
+                               Label* call_runtime);
+
  private:
   Register object_;
   Register index_;
   Register result_;
 
   Label* receiver_not_string_;
   Label* index_not_number_;
   Label* index_out_of_range_;
 
   StringIndexFlags index_flags_;
@@ skipping 255 matching lines @@
   int MinorKey() { return 0; }
 
   void Generate(MacroAssembler* masm);
 
   DISALLOW_COPY_AND_ASSIGN(StoreArrayLiteralElementStub);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_