backport: re PR fortran/91557 (Bogus warning about unused dummy argument _formal_*)

backport: re PR fortran/91557 (Bogus warning about unused dummy argument _formal_*)

2019-09-15  Thomas Koenig  <tkoenig@gcc.gnu.org>

    Backport from trunk
    PR fortran/91557
    * trans-decl.c (generate_local_decl): Do not warn if the symbol
    is artificial.
    * trans-types.c (get_formal_from_actual_arglist): Set artificial
    attribute on dummy arguments.

2019-09-15  Thomas Koenig  <tkoenig@gcc.gnu.org>

    Backport from trunk
    PR fortran/91557
    * gfortran.dg/warn_unused_dummy_argument_5.f90: New test.

From-SVN: r275733