[stubs] replaced ToString MacroAssembler Stub with CodeStubAssembler builtin

src/code-stubs.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_CODE_STUBS_H_
 #define V8_CODE_STUBS_H_
 
 #include "src/allocation.h"
 #include "src/assembler.h"
 #include "src/code-stub-assembler.h"
@@ skipping 25 matching lines @@
   V(InternalArrayConstructor)                 \
   V(JSEntry)                                  \
   V(LoadIndexedString)                        \
   V(MathPow)                                  \
   V(ProfileEntryHook)                         \
   V(RecordWrite)                              \
   V(RegExpExec)                               \
   V(StoreBufferOverflow)                      \
   V(StoreElement)                             \
   V(SubString)                                \
-  V(ToString)                                 \
   V(StoreIC)                                  \
   V(KeyedStoreIC)                             \
   V(KeyedLoadIC)                              \
   V(LoadIC)                                   \
   V(LoadGlobalIC)                             \
   V(FastNewObject)                            \
   V(FastNewRestParameter)                     \
   V(FastNewSloppyArguments)                   \
   V(FastNewStrictArguments)                   \
   V(NameDictionaryLookup)                     \
@@ skipping 3050 matching lines @@
                                assembler->Parameter(Descriptor::kString),
                                assembler->Parameter(Descriptor::kFrom),
                                assembler->Parameter(Descriptor::kTo),
                                assembler->Parameter(Descriptor::kContext)));
   }
 
   DEFINE_CALL_INTERFACE_DESCRIPTOR(SubString);
   DEFINE_CODE_STUB(SubString, TurboFanCodeStub);
 };
 
-class ToStringStub final : public PlatformCodeStub {
- public:
-  explicit ToStringStub(Isolate* isolate) : PlatformCodeStub(isolate) {}
-
-  DEFINE_CALL_INTERFACE_DESCRIPTOR(TypeConversion);
-  DEFINE_PLATFORM_CODE_STUB(ToString, PlatformCodeStub);
-};
-
 class ToObjectStub final : public TurboFanCodeStub {
  public:
   explicit ToObjectStub(Isolate* isolate) : TurboFanCodeStub(isolate) {}
 
   DEFINE_CALL_INTERFACE_DESCRIPTOR(TypeConversion);
   DEFINE_TURBOFAN_CODE_STUB(ToObject, TurboFanCodeStub);
 };
 
 #undef DEFINE_CALL_INTERFACE_DESCRIPTOR
 #undef DEFINE_PLATFORM_CODE_STUB
 #undef DEFINE_HANDLER_CODE_STUB
 #undef DEFINE_HYDROGEN_CODE_STUB
 #undef DEFINE_CODE_STUB
 #undef DEFINE_CODE_STUB_BASE
 
 extern Representation RepresentationFromMachineType(MachineType type);
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CODE_STUBS_H_