[Bug fortran/120355] [15/16 Regression] Type mismatch for passed external function, if external function appears in the same source file

[anlauf at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120355

--- Comment #1 from anlauf at gcc dot gnu.org ---
Workaround: don't use the result clause in the external function, e.g.

integer function s(x)
  implicit none
  integer, intent(in) :: x
  s = 1 - x
end function s