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

src/mips64/interface-descriptors-mips64.cc

Index: src/mips64/interface-descriptors-mips64.cc
diff --git a/src/mips64/interface-descriptors-mips64.cc b/src/mips64/interface-descriptors-mips64.cc
index 8759bdd9bd3932e0a790faeb63423a06eee6eaf2..06db80883124ff26cb5ca164650f7a6c67296293 100644
--- a/src/mips64/interface-descriptors-mips64.cc
+++ b/src/mips64/interface-descriptors-mips64.cc
@@ -29,6 +29,9 @@ const Register StoreDescriptor::NameRegister() { return a2; }
 const Register StoreDescriptor::ValueRegister() { return a0; }
 
 
+const Register ExtendStorageDescriptor::MapRegister() { return a3; }
+
+
 const Register ElementTransitionAndStoreDescriptor::MapRegister() { return a3; }