gcc/fortran/ChangeLog:
* doc/gfortran/naming-and-argument-passing-conventions.rst:
Revert.
passed by value.
For ``OPTIONAL`` dummy arguments, an absent argument is denoted
-by a NULL pointer, except for scalar dummy arguments of intrinsic type
+by a NULL pointer, except for scalar dummy arguments of type
+``INTEGER``, ``LOGICAL``, ``REAL`` and ``COMPLEX``
which have the ``VALUE`` attribute. For those, a hidden Boolean
argument (``logical(kind=C_bool),value``) is used to indicate
whether the argument is present.