[runtime] Add %ToString and %_ToString and remove the TO_STRING builtin.

src/interface-descriptors.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_CALL_INTERFACE_DESCRIPTOR_H_
 #define V8_CALL_INTERFACE_DESCRIPTOR_H_
 
 #include "src/assembler.h"
 #include "src/macro-assembler.h"
 
 namespace v8 {
 namespace internal {
 
 class PlatformInterfaceDescriptor;
 
 #define INTERFACE_DESCRIPTOR_LIST(V)          \
   V(Load)                                     \
   V(Store)                                    \
   V(StoreTransition)                          \
   V(VectorStoreTransition)                    \
   V(VectorStoreICTrampoline)                  \
   V(VectorStoreIC)                            \
   V(InstanceOf)                               \
   V(LoadWithVector)                           \
   V(FastNewClosure)                           \
   V(FastNewContext)                           \
   V(ToNumber)                                 \
+  V(ToString)                                 \
   V(ToObject)                                 \
   V(NumberToString)                           \
   V(Typeof)                                   \
   V(FastCloneShallowArray)                    \
   V(FastCloneShallowObject)                   \
   V(CreateAllocationSite)                     \
   V(CreateWeakCell)                           \
   V(CallFunction)                             \
   V(CallFunctionWithFeedback)                 \
   V(CallFunctionWithFeedbackAndVector)        \
@@ skipping 318 matching lines @@
   DECLARE_DESCRIPTOR(FastNewContextDescriptor, CallInterfaceDescriptor)
 };
 
 
 class ToNumberDescriptor : public CallInterfaceDescriptor {
  public:
   DECLARE_DESCRIPTOR(ToNumberDescriptor, CallInterfaceDescriptor)
 };
 
 
+class ToStringDescriptor : public CallInterfaceDescriptor {
+ public:
+  enum ParameterIndices { kReceiverIndex };
+
+  DECLARE_DESCRIPTOR(ToStringDescriptor, CallInterfaceDescriptor)
+
+  static const Register ReceiverRegister();
+};
+
+
 class ToObjectDescriptor : public CallInterfaceDescriptor {
  public:
   enum ParameterIndices { kReceiverIndex };
 
   DECLARE_DESCRIPTOR(ToObjectDescriptor, CallInterfaceDescriptor)
 
   static const Register ReceiverRegister();
 };
 
 
@@ skipping 299 matching lines @@
 }  // namespace v8::internal
 
 
 #if V8_TARGET_ARCH_ARM64
 #include "src/arm64/interface-descriptors-arm64.h"
 #elif V8_TARGET_ARCH_ARM
 #include "src/arm/interface-descriptors-arm.h"
 #endif
 
 #endif  // V8_CALL_INTERFACE_DESCRIPTOR_H_