Revert of [turbofan] Speculatively optimize string character access.

src/heap/heap.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_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 #include <vector>
 
@@ skipping 154 matching lines @@
   V(FixedArray, empty_sloppy_arguments_elements, EmptySloppyArgumentsElements) \
   V(SeededNumberDictionary, empty_slow_element_dictionary,                     \
     EmptySlowElementDictionary)                                                \
   V(PropertyCell, empty_property_cell, EmptyPropertyCell)                      \
   V(WeakCell, empty_weak_cell, EmptyWeakCell)                                  \
   V(InterceptorInfo, noop_interceptor_info, NoOpInterceptorInfo)               \
   /* Protectors */                                                             \
   V(PropertyCell, array_protector, ArrayProtector)                             \
   V(Cell, is_concat_spreadable_protector, IsConcatSpreadableProtector)         \
   V(Cell, species_protector, SpeciesProtector)                                 \
-  V(Cell, string_bounds_check_protector, StringBoundsCheckProtector)           \
   V(PropertyCell, string_length_protector, StringLengthProtector)              \
   V(Cell, fast_array_iteration_protector, FastArrayIterationProtector)         \
   V(PropertyCell, array_iterator_protector, ArrayIteratorProtector)            \
   V(PropertyCell, array_buffer_neutering_protector,                            \
     ArrayBufferNeuteringProtector)                                             \
   /* Special numbers */                                                        \
   V(HeapNumber, nan_value, NanValue)                                           \
   V(HeapNumber, hole_nan_value, HoleNanValue)                                  \
   V(HeapNumber, infinity_value, InfinityValue)                                 \
   V(HeapNumber, minus_zero_value, MinusZeroValue)                              \
@@ skipping 2472 matching lines @@
   friend class PagedSpace;
   DISALLOW_COPY_AND_ASSIGN(AllocationObserver);
 };
 
 V8_EXPORT_PRIVATE const char* AllocationSpaceName(AllocationSpace space);
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_HEAP_H_