Revert of [turbofan] Speculatively optimize string character access.

src/heap/heap.cc

 // 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.
 
 #include "src/heap/heap.h"
 
 #include <unordered_map>
 #include <unordered_set>
 
 #include "src/accessors.h"
@@ skipping 2837 matching lines @@
   set_array_iterator_protector(*cell);
 
   Handle<Cell> is_concat_spreadable_cell = factory->NewCell(
       handle(Smi::FromInt(Isolate::kProtectorValid), isolate()));
   set_is_concat_spreadable_protector(*is_concat_spreadable_cell);
 
   Handle<Cell> species_cell = factory->NewCell(
       handle(Smi::FromInt(Isolate::kProtectorValid), isolate()));
   set_species_protector(*species_cell);
 
-  Handle<Cell> string_bounds_check_cell = factory->NewCell(
-      handle(Smi::FromInt(Isolate::kProtectorValid), isolate()));
-  set_string_bounds_check_protector(*string_bounds_check_cell);
-
   cell = factory->NewPropertyCell();
   cell->set_value(Smi::FromInt(Isolate::kProtectorValid));
   set_string_length_protector(*cell);
 
   Handle<Cell> fast_array_iteration_cell = factory->NewCell(
       handle(Smi::FromInt(Isolate::kProtectorValid), isolate()));
   set_fast_array_iteration_protector(*fast_array_iteration_cell);
 
   cell = factory->NewPropertyCell();
   cell->set_value(Smi::FromInt(Isolate::kProtectorValid));
@@ skipping 3704 matching lines @@
     case LO_SPACE:
       return "LO_SPACE";
     default:
       UNREACHABLE();
   }
   return NULL;
 }
 
 }  // namespace internal
 }  // namespace v8