[Atomics] code stubs for atomic operations

src/interface-descriptors.h

Index: src/interface-descriptors.h
diff --git a/src/interface-descriptors.h b/src/interface-descriptors.h
index 6a5e1fa5efd97ed7958d34a3a4914687b6933988..7e26f5e8a877e9a33e7b1692727f2680dffb2322 100644
--- a/src/interface-descriptors.h
+++ b/src/interface-descriptors.h
@@ -79,7 +79,8 @@ class PlatformInterfaceDescriptor;
   V(InterpreterDispatch)                      \
   V(InterpreterPushArgsAndCall)               \
   V(InterpreterPushArgsAndConstruct)          \
-  V(InterpreterCEntry)
+  V(InterpreterCEntry)                        \
+  V(AtomicsLoad)
 
 class CallInterfaceDescriptorData {
  public:
@@ -786,6 +787,13 @@ class InterpreterCEntryDescriptor : public CallInterfaceDescriptor {
   DECLARE_DESCRIPTOR(InterpreterCEntryDescriptor, CallInterfaceDescriptor)
 };
 
+
+class AtomicsLoadDescriptor : public CallInterfaceDescriptor {
+ public:
+  DECLARE_DESCRIPTOR(AtomicsLoadDescriptor, CallInterfaceDescriptor)
+};
+
+
 #undef DECLARE_DESCRIPTOR