[temp.func.order] Explicitly specify to only add extra first argument if we have an implicit object argument

In [temp.func.order] paragraph 3, it is written that we need to add a new first parameter for all member functions for the purposes of template deduction. However, it only makes sense if we have an implicit object parameter.

If we don't have an implicit object parameter, we shouldn't add a new first parameter because all of our parameters explicitly are written.

Author: HoBoIs

source/templates.tex

@@ -3903,7 +3903,7 @@
 in the type of the value synthesized for a non-type template parameter
 is also a unique synthesized type.
 \end{note}
-Each function template $M$ that is a member function
+Each function template $M$ that is a member function with an implicit object parameter
 is considered to have
 a new first parameter of type $X(M)$, described below,
 inserted in its function parameter list.