[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 378f0ce6f907f5fb4e5dee4f39f2128ce4e9f7bc..f41bc647e949a0912cacda552d99316db76ec7b6 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:
@@ -827,6 +828,11 @@ 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