Fortran: allow RESTRICT qualifier also for optional arguments [PR100988]
gcc/fortran/ChangeLog:
PR fortran/100988
* gfortran.h (IS_PROC_POINTER): New macro.
* trans-types.cc (gfc_sym_type): Use macro in determination if the
restrict qualifier can be used for a dummy variable. Fix logic to
allow the restrict qualifier also for optional arguments, and to
not apply it to pointer or proc_pointer arguments.