PPC/s390: [stubs] Drop CallApiCallbackStub::call_data_undefined optimization.

src/s390/code-stubs-s390.cc

 // Copyright 2014 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/code-stubs.h"
 #include "src/api-arguments.h"
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
@@ skipping 2857 matching lines @@
     __ LoadP(context, FieldMemOperand(callee, JSFunction::kContextOffset));
   }
 
   // callee
   __ push(callee);
 
   // call data
   __ push(call_data);
 
   Register scratch = call_data;
-  if (!call_data_undefined()) {
-    __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
-  }
+  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
   // return value
   __ push(scratch);
   // return value default
   __ push(scratch);
   // isolate
   __ mov(scratch, Operand(ExternalReference::isolate_address(masm->isolate())));
   __ push(scratch);
   // holder
   __ push(holder);
 
@@ skipping 143 matching lines @@
   CallApiFunctionAndReturn(masm, api_function_address, thunk_ref,
                            kStackUnwindSpace, NULL, return_value_operand, NULL);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_S390