[stubs] Remove unused StoreGlobalViaContextStub.

src/s390/interface-descriptors-s390.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_S390
 
 #include "src/interface-descriptors.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 24 matching lines @@
 const Register StoreDescriptor::NameRegister() { return r4; }
 const Register StoreDescriptor::ValueRegister() { return r2; }
 const Register StoreDescriptor::SlotRegister() { return r6; }
 
 const Register StoreWithVectorDescriptor::VectorRegister() { return r5; }
 
 const Register StoreTransitionDescriptor::SlotRegister() { return r6; }
 const Register StoreTransitionDescriptor::VectorRegister() { return r5; }
 const Register StoreTransitionDescriptor::MapRegister() { return r7; }
 
-const Register StoreGlobalViaContextDescriptor::SlotRegister() { return r4; }
-const Register StoreGlobalViaContextDescriptor::ValueRegister() { return r2; }
-
 const Register StringCompareDescriptor::LeftRegister() { return r3; }
 const Register StringCompareDescriptor::RightRegister() { return r2; }
 
 const Register ApiGetterDescriptor::HolderRegister() { return r2; }
 const Register ApiGetterDescriptor::CallbackRegister() { return r5; }
 
 const Register MathPowTaggedDescriptor::exponent() { return r4; }
 
 const Register MathPowIntegerDescriptor::exponent() {
   return MathPowTaggedDescriptor::exponent();
@@ skipping 333 matching lines @@
       r3,  // the JSGeneratorObject to resume
       r4   // the resume mode (tagged)
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_S390