Wrong GNAT warning. How to suppress it?

[Victor Porton <porton@narod.ru>]

How to eliminate the GNAT warning in the below program?

$ gcc-7 -c main.adb
main.adb:13:05: warning: "return" statement missing following this statement
main.adb:13:05: warning: Program_Error may be raised at run time


procedure Main is

  procedure My_Raise is
  begin
    raise Constraint_Error;
  end;

  function F (I: Integer) return Integer is
  begin
    if I = 0 then
      return 1;
    end if;
    My_Raise;
  end;

begin
  null;
end;

-- 
Victor Porton - http://portonvictor.org