[turbofan] Add new StringFromCharCode simplified operator.

src/compiler/access-builder.cc

 // 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.
 
 #include "src/compiler/access-builder.h"
 
 #include "src/contexts.h"
 #include "src/frames.h"
 #include "src/handles-inl.h"
 #include "src/heap/heap.h"
@@ skipping 347 matching lines @@
 // static
 FieldAccess AccessBuilder::ForMapPrototype() {
   FieldAccess access = {
       kTaggedBase,           Map::kPrototypeOffset,    Handle<Name>(),
       Type::TaggedPointer(), MachineType::AnyTagged(), kPointerWriteBarrier};
   return access;
 }
 
 
 // static
+FieldAccess AccessBuilder::ForNameHashField() {
+  FieldAccess access = {
+      kTaggedBase,      Name::kHashFieldOffset, Handle<Name>(),
+      Type::Internal(), MachineType::Pointer(), kNoWriteBarrier};
+  return access;
+}
+
+// static
 FieldAccess AccessBuilder::ForStringLength() {
   FieldAccess access = {kTaggedBase,
                         String::kLengthOffset,
                         Handle<Name>(),
                         TypeCache::Get().kStringLengthType,
                         MachineType::AnyTagged(),
                         kNoWriteBarrier};
   return access;
 }
 
@@ skipping 161 matching lines @@
   }
   UNREACHABLE();
   ElementAccess access = {kUntaggedBase, 0, Type::None(), MachineType::None(),
                           kNoWriteBarrier};
   return access;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8