* gfortran.dg/do_iterator: Split loop, markup all lines for
which an error locus is printed.
* gfortran.dg/pr17708.f90: Markup all lines for which an error
locus is printed.
* gfortran.dg/select_4.f90: Likewise.
* lib/gfortran-dg.exp (gfortran-dg-test): Handle gfortran error
locuses in the various permutations.

From-SVN: r95329