match.c (gfc_match_stopcode): Permit error stop in pure procedures with F2015.

gcc/fortran/
2014-12-31  Tobias Burnus  <burnus@net-b.de>

        * match.c (gfc_match_stopcode): Permit error stop in pure
        procedures with F2015.

gcc/testsuite/
2014-12-31  Tobias Burnus  <burnus@net-b.de>

        * gfortran.dg/error_stop_3.f90: New.
        * gfortran.dg/error_stop_4.f90: New.
        * gfortran.dg/coarray_3.f90: Remove a dg-error.

From-SVN: r219127