[Atomics] code stubs for atomic operations

src/mips/interface-descriptors-mips.cc

Index: src/mips/interface-descriptors-mips.cc
diff --git a/src/mips/interface-descriptors-mips.cc b/src/mips/interface-descriptors-mips.cc
index 7ab2445744cf3ee1b98adfd3b7fbb26a10abdf3d..17e8aecb172b464e8260c78c5f0f5f050b2c56d3 100644
--- a/src/mips/interface-descriptors-mips.cc
+++ b/src/mips/interface-descriptors-mips.cc
@@ -424,6 +424,15 @@ void ResumeGeneratorDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
+void AtomicsLoadDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  Register registers[] = {
+      a1,  // the typedarray object
+      a0   // the index to load (untagged)
+  };
+  data->InitializePlatformSpecific(arraysize(registers), registers);
+}
+
 }  // namespace internal
 }  // namespace v8