ExtendStorageStub added, it is aimed for extending objects backing store when it runs out of space.

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 936ce20acc358138c314e910ab8ce45b88758e1a..04492b403a42f156bc322218889e375994d567c3 100644
--- a/src/mips/interface-descriptors-mips.cc
+++ b/src/mips/interface-descriptors-mips.cc
@@ -27,6 +27,9 @@ const Register VectorLoadICDescriptor::VectorRegister() { return a3; }
 const Register StoreDescriptor::ReceiverRegister() { return a1; }
 const Register StoreDescriptor::NameRegister() { return a2; }
 const Register StoreDescriptor::ValueRegister() { return a0; }
+const Register ExtendStorageDescriptor::MapRegister() {
+  return StoreDescriptor::NameRegister();
+}
 
 
 const Register ElementTransitionAndStoreDescriptor::MapRegister() { return a3; }