Revert "DWARF and unwind support for AOT assembly output."

runtime/vm/native_symbol.h

 // 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.
 
 #ifndef RUNTIME_VM_NATIVE_SYMBOL_H_
 #define RUNTIME_VM_NATIVE_SYMBOL_H_
 
 #include "vm/allocation.h"
 #include "vm/globals.h"
 
 namespace dart {
 
 class Mutex;
 
 class NativeSymbolResolver : public AllStatic {
  public:
   static void InitOnce();
   static void ShutdownOnce();
   static char* LookupSymbolName(uintptr_t pc, uintptr_t* start);
-  static bool LookupSharedObject(uword pc, uword* dso_base, char** dso_name);
   static void FreeSymbolName(char* name);
 };
 
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_NATIVE_SYMBOL_H_