Revision 168665 caused/exposed the following ICE at -O2 or above:

[macbook] f90/bug% gfc6 -O2 pr35971_red.f90
pr35971_red.f90: In function 'gp':
pr35971_red.f90:67:0: error: non-trivial conversion at assignment
void (*<T64>) (void)
void (*<T49d>) (struct array1_unknown &, integer(kind=4), struct array1_integer(kind=4) & restrict)
__result_gp_72 = make_mess;

pr35971_red.f90:67:0: internal compiler error: verify_stmts failed

with the following (probably invalid?) code

[macbook] f90/bug% cat pr35971_red.f90
module other_fun
   use ISO_C_BINDING
   implicit none
   private
! Message to be returned by procedure pointed to
! by the C_FUNPTR
   character, allocatable, save :: my_message(:)
! Interface block for the procedure pointed to
! by the C_FUNPTR
   public abstract_fun
   abstract interface
      function abstract_fun(x)
         use ISO_C_BINDING
         import my_message
         implicit none
         integer(C_INT) x(:)
         character(size(my_message),C_CHAR) abstract_fun(size(x))
      end function abstract_fun
   end interface
   contains
! Procedure to store the message and get the C_FUNPTR
      function gp(message) bind(C,name='BlAh')
!         procedure(abstract_fun) make_mess
         character(kind=C_CHAR) message(*)
         type(C_FUNPTR) gp
         integer(C_INT64_T) i

         i = 1
         do while(message(i) /= C_NULL_CHAR)
            i = i+1
         end do
         my_message = message(int(1,kind(i)):i-1)
         gp = get_funloc(make_mess,aux)
!         gp = aux(make_mess)
      end function gp

! Intermediate procedure to pass the function and get
! back the C_FUNPTR
      function get_funloc(x,y)
         procedure(abstract_fun) x
         type(C_FUNPTR) y
         external y
         type(C_FUNPTR) get_funloc

         get_funloc = y(x)
      end function get_funloc

! Procedure to convert the function to C_FUNPTR
      function aux(x)
         interface
            subroutine x() bind(C)
            end subroutine x
         end interface
         type(C_FUNPTR) aux

         aux = C_FUNLOC(x)
      end function aux

! Procedure pointed to by the C_FUNPTR
      function make_mess(x)
         integer(C_INT) x(:)
         character(size(my_message),C_CHAR) make_mess(size(x))

         make_mess = transfer(my_message,make_mess(1))
      end function make_mess
end module other_fun
end