[stubs] Optimize LoadGlobalViaContextStub and StoreGlobalViaContextStub.

src/x64/interface-descriptors-x64.cc

Index: src/x64/interface-descriptors-x64.cc
diff --git a/src/x64/interface-descriptors-x64.cc b/src/x64/interface-descriptors-x64.cc
index f59b67d78fe626ca4dd50bb07dfb6489b0bb9017..e9579899a0f82e174e78332c1cfbdb160b8fec73 100644
--- a/src/x64/interface-descriptors-x64.cc
+++ b/src/x64/interface-descriptors-x64.cc
@@ -36,12 +36,10 @@ const Register VectorStoreICDescriptor::VectorRegister() { return rbx; }
 const Register StoreTransitionDescriptor::MapRegister() { return rbx; }
 
 
-const Register LoadGlobalViaContextDescriptor::DepthRegister() { return rdx; }
 const Register LoadGlobalViaContextDescriptor::SlotRegister() { return rbx; }
 const Register LoadGlobalViaContextDescriptor::NameRegister() { return rcx; }
 
 
-const Register StoreGlobalViaContextDescriptor::DepthRegister() { return rdx; }
 const Register StoreGlobalViaContextDescriptor::SlotRegister() { return rbx; }
 const Register StoreGlobalViaContextDescriptor::NameRegister() { return rcx; }
 const Register StoreGlobalViaContextDescriptor::ValueRegister() { return rax; }