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

src/arm64/interface-descriptors-arm64.cc

Index: src/arm64/interface-descriptors-arm64.cc
diff --git a/src/arm64/interface-descriptors-arm64.cc b/src/arm64/interface-descriptors-arm64.cc
index 30717916c34bd6a27ff9787ba9064294e5bc2cf4..13ecc2b982c1ac1b8223cefb683dc200e62f7e31 100644
--- a/src/arm64/interface-descriptors-arm64.cc
+++ b/src/arm64/interface-descriptors-arm64.cc
@@ -31,9 +31,9 @@ const Register LoadDescriptor::ReceiverRegister() { return x1; }
 const Register LoadDescriptor::NameRegister() { return x2; }
 const Register LoadDescriptor::SlotRegister() { return x0; }
 
-
 const Register LoadWithVectorDescriptor::VectorRegister() { return x3; }
 
+const Register LoadICProtoArrayDescriptor::HandlerRegister() { return x4; }
 
 const Register StoreDescriptor::ReceiverRegister() { return x1; }
 const Register StoreDescriptor::NameRegister() { return x2; }