[ic] Extract load IC proto array handlers handling to a separate stub.

src/s390/interface-descriptors-s390.cc

Index: src/s390/interface-descriptors-s390.cc
diff --git a/src/s390/interface-descriptors-s390.cc b/src/s390/interface-descriptors-s390.cc
index 04f2f1ed665e4b63dd1e956d546902cf2fd8850c..7fdf99349e1cf54a7078fce81dba68498ea0d1f4 100644
--- a/src/s390/interface-descriptors-s390.cc
+++ b/src/s390/interface-descriptors-s390.cc
@@ -31,6 +31,8 @@ const Register LoadDescriptor::SlotRegister() { return r2; }
 
 const Register LoadWithVectorDescriptor::VectorRegister() { return r5; }
 
+const Register LoadICProtoArrayDescriptor::HandlerRegister() { return r6; }
+
 const Register StoreDescriptor::ReceiverRegister() { return r3; }
 const Register StoreDescriptor::NameRegister() { return r4; }
 const Register StoreDescriptor::ValueRegister() { return r2; }