Remove passing of argc in r0 when calling builtins on ARM as it is not used

src/arm/virtual-frame-arm.h

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 287 matching lines @@
 
   // Call runtime given the number of arguments expected on (and
   // removed from) the stack.
   void CallRuntime(Runtime::Function* f, int arg_count);
   void CallRuntime(Runtime::FunctionId id, int arg_count);
 
   // Invoke builtin given the number of arguments it expects on (and
   // removes from) the stack.
   void InvokeBuiltin(Builtins::JavaScript id,
                      InvokeJSFlags flag,
-                     Result* arg_count_register,
                      int arg_count);
 
   // Call into an IC stub given the number of arguments it removes
   // from the stack.  Register arguments are passed as results and
   // consumed by the call.
   void CallCodeObject(Handle<Code> ic,
                       RelocInfo::Mode rmode,
                       int dropped_args);
   void CallCodeObject(Handle<Code> ic,
                       RelocInfo::Mode rmode,
@@ skipping 197 matching lines @@
 
   // Classes that need raw access to the elements_ array.
   friend class DeferredCode;
   friend class JumpTarget;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_VIRTUAL_FRAME_ARM_H_