[stubs] Drop CallApiCallbackStub::call_data_undefined optimization.

src/mips64/code-stubs-mips64.cc

 // Copyright 2012 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_MIPS64
 
 #include "src/code-stubs.h"
 #include "src/api-arguments.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 2958 matching lines @@
   __ PushRoot(Heap::kUndefinedValueRootIndex);
 
   // Save context, callee and call data.
   __ Push(context, callee, call_data);
   if (!is_lazy()) {
     // Load context from callee.
     __ Ld(context, FieldMemOperand(callee, JSFunction::kContextOffset));
   }
 
   Register scratch = call_data;
-  if (!call_data_undefined()) {
-    __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
-  }
+  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
   // Push return value and default return value.
   __ Push(scratch, scratch);
   __ li(scratch, Operand(ExternalReference::isolate_address(masm->isolate())));
   // Push isolate and holder.
   __ Push(scratch, holder);
 
   // Prepare arguments.
   __ mov(scratch, sp);
 
   // Allocate the v8::Arguments structure in the arguments' space since
@@ skipping 115 matching lines @@
                            kStackUnwindSpace, kInvalidStackOffset,
                            return_value_operand, NULL);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS64