[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 12f5618205040bc5262fae3e39a2444512bce611..ac2062a5dac2901f14f6cc05fa10409ec126c28d 100644
--- a/src/interface-descriptors.h
+++ b/src/interface-descriptors.h
@@ -91,7 +91,8 @@ class PlatformInterfaceDescriptor;
   V(InterpreterPushArgsAndCall)               \
   V(InterpreterPushArgsAndConstruct)          \
   V(InterpreterCEntry)                        \
-  V(ResumeGenerator)
+  V(ResumeGenerator)                          \
+  V(AtomicsLoad)
 
 class CallInterfaceDescriptorData {
  public:
@@ -828,6 +829,11 @@ class ResumeGeneratorDescriptor final : public CallInterfaceDescriptor {
   DECLARE_DESCRIPTOR(ResumeGeneratorDescriptor, 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