[turbofan] Add support for String.prototype.charCodeAt/charAt.

src/compiler/access-builder.h

 // Copyright 2014 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_COMPILER_ACCESS_BUILDER_H_
 #define V8_COMPILER_ACCESS_BUILDER_H_
 
 #include "src/compiler/simplified-operator.h"
 
 namespace v8 {
@@ skipping 106 matching lines @@
 
   // Provides access to Map::prototype() field.
   static FieldAccess ForMapPrototype();
 
   // Provides access to Name::hash_field() field.
   static FieldAccess ForNameHashField();
 
   // Provides access to String::length() field.
   static FieldAccess ForStringLength();
 
+  // Provides access to ConsString::first() field.
+  static FieldAccess ForConsStringFirst();
+
+  // Provides access to ConsString::second() field.
+  static FieldAccess ForConsStringSecond();
+
+  // Provides access to SlicedString::offset() field.
+  static FieldAccess ForSlicedStringOffset();
+
+  // Provides access to SlicedString::parent() field.
+  static FieldAccess ForSlicedStringParent();
+
+  // Provides access to ExternalString::resource_data() field.
+  static FieldAccess ForExternalStringResourceData();
+
+  // Provides access to ExternalOneByteString characters.
+  static ElementAccess ForExternalOneByteStringCharacter();
+
+  // Provides access to ExternalTwoByteString characters.
+  static ElementAccess ForExternalTwoByteStringCharacter();
+
+  // Provides access to SeqOneByteString characters.
+  static ElementAccess ForSeqOneByteStringCharacter();
+
+  // Provides access to SeqTwoByteString characters.
+  static ElementAccess ForSeqTwoByteStringCharacter();
+
   // Provides access to JSGlobalObject::global_proxy() field.
   static FieldAccess ForJSGlobalObjectGlobalProxy();
 
   // Provides access to JSGlobalObject::native_context() field.
   static FieldAccess ForJSGlobalObjectNativeContext();
 
   // Provides access to JSValue::value() field.
   static FieldAccess ForValue();
 
   // Provides access to arguments object fields.
@@ skipping 22 matching lines @@
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(AccessBuilder);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_ACCESS_BUILDER_H_