[Atomics] code stubs for atomic operations

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"
 
@@ skipping 72 matching lines @@
   V(ApiGetter)                                \
   V(LoadGlobalViaContext)                     \
   V(StoreGlobalViaContext)                    \
   V(MathPowTagged)                            \
   V(MathPowInteger)                           \
   V(ContextOnly)                              \
   V(GrowArrayElements)                        \
   V(InterpreterDispatch)                      \
   V(InterpreterPushArgsAndCall)               \
   V(InterpreterPushArgsAndConstruct)          \
-  V(InterpreterCEntry)
+  V(InterpreterCEntry)                        \
+  V(AtomicsLoad)
 
 class CallInterfaceDescriptorData {
  public:
   CallInterfaceDescriptorData()
       : register_param_count_(-1), function_type_(nullptr) {}
 
   // A copy of the passed in registers and param_representations is made
   // and owned by the CallInterfaceDescriptorData.
 
   void InitializePlatformIndependent(FunctionType* function_type) {
@@ skipping 711 matching lines @@
   DECLARE_DESCRIPTOR(InterpreterPushArgsAndConstructDescriptor,
                      CallInterfaceDescriptor)
 };
 
 
 class InterpreterCEntryDescriptor : public CallInterfaceDescriptor {
  public:
   DECLARE_DESCRIPTOR(InterpreterCEntryDescriptor, CallInterfaceDescriptor)
 };
 
+class AtomicsLoadDescriptor : public CallInterfaceDescriptor {
+ public:
+  DECLARE_DESCRIPTOR(AtomicsLoadDescriptor, CallInterfaceDescriptor)
+};
+
 #undef DECLARE_DESCRIPTOR_WITH_BASE
 #undef DECLARE_DESCRIPTOR
 #undef DECLARE_DESCRIPTOR_WITH_CUSTOM_FUNCTION_TYPE
 #undef DECLARE_DESCRIPTOR_WITH_BASE_AND_FUNCTION_TYPE_ARG
 
 // We define the association between CallDescriptors::Key and the specialized
 // descriptor here to reduce boilerplate and mistakes.
 #define DEF_KEY(name) \
   CallDescriptors::Key name##Descriptor::key() { return CallDescriptors::name; }
 INTERFACE_DESCRIPTOR_LIST(DEF_KEY)
 #undef DEF_KEY
 }  // namespace internal
 }  // namespace v8
 
 
 #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_