Code should be retrieved via the AST id, not via the source position. Bugs like

src/type-info.cc

 // 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 222 matching lines @@
       // TODO(kasperl): We really need a type for JS objects here.
       return TypeInfo::NonPrimitive();
     case CompareIC::GENERIC:
     default:
       return unknown;
   }
 }
 
 
 TypeInfo TypeFeedbackOracle::UnaryType(UnaryOperation* expr) {
-  Handle<Object> object = GetInfo(expr->position());
+  Handle<Object> object = GetInfo(expr->id());
   TypeInfo unknown = TypeInfo::Unknown();
   if (!object->IsCode()) return unknown;
   Handle<Code> code = Handle<Code>::cast(object);
   ASSERT(code->is_type_recording_unary_op_stub());
   TRUnaryOpIC::TypeInfo type = static_cast<TRUnaryOpIC::TypeInfo>(
       code->type_recording_unary_op_type());
   switch (type) {
     case TRUnaryOpIC::SMI:
       return TypeInfo::Smi();
     case TRUnaryOpIC::HEAP_NUMBER:
@@ skipping 229 matching lines @@
           static_cast<int>(info->pc() - code->instruction_start()));
       ASSERT(ast_ids->length() == 0 ||
              (*ast_ids)[ast_ids->length()-1] !=
              static_cast<unsigned>(info->data()));
       ast_ids->Add(static_cast<unsigned>(info->data()));
     }
   }
 }
 
 } }  // namespace v8::internal