[Atomics] code stubs for atomic operations

src/arm64/interface-descriptors-arm64.cc

 // Copyright 2012 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.
 
 #include "src/arm64/interface-descriptors-arm64.h"
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/interface-descriptors.h"
 
@@ skipping 459 matching lines @@
 void ResumeGeneratorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       x0,  // the value to pass to the generator
       x1,  // the JSGeneratorObject to resume
       x2   // the resume mode (tagged)
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
+void AtomicsLoadDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  Register registers[] = {
+      x1,  // the typedarray object
+      x0   // the index to load (untagged)
+  };
+  data->InitializePlatformSpecific(arraysize(registers), registers);
+}
+
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM64