This patch fixes the above PRs and the additional problems in comment
#1 of both 82606 and 82622.

For the main part, the patch consists of 'obvious' tweaks to the PDT
machinery. The exception to this is the chunk in
trans-array.c(set_loop_bounds), which is needed to handle
parameterized array components coming from trans-io.c. This is safe
because the code would have fallen through to gcc_unreachable
otherwise. If the info->end is present then this can be used.

Bootstrapped and regtested on FC23/x86_64 - OK for trunk?

I will commit tomorrow morning if there are no complaints in the meantime.

Regards

Paul

2017-11-30  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/82605
    * resolve.c (get_pdt_constructor): Initialize 'cons' to NULL.
    (resolve_pdt): Correct typo in prior comment. Emit an error if
    any parameters are deferred and the object is neither pointer
    nor allocatable.

    PR fortran/82606
    * decl.c (gfc_get_pdt_instance): Continue if the parameter sym
    is not present or has no name. Select the parameter by name
    of component, rather than component order. Remove all the other
    manipulations of 'tail' when building the pdt instance.
    (gfc_match_formal_arglist): Emit and error if a star is picked
    up in a PDT decl parameter list.

    PR fortran/82622
    * trans-array.c (set_loop_bounds): If a GFC_SS_COMPONENT has an
    info->end, use it rather than falling through to
    gcc_unreachable.
    (structure_alloc_comps): Check that param->name is non-null
    before comparing with the component name.
    * trans-decl.c (gfc_get_symbol_decl): Do not use the static
    initializer for PDT symbols.
    (gfc_init_default_dt): Do nothing for PDT symbols.
    * trans-io.c (transfer_array_component): Parameterized array
    components use the descriptor ubound since the shape is not
    available.

2017-11-30  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/82605
    * gfortran.dg/pdt_4.f03 : Incorporate the new error.

    PR fortran/82606
    * gfortran.dg/pdt_19.f03 : New test.
    * gfortran.dg/pdt_21.f03 : New test.

    PR fortran/82622
    * gfortran.dg/pdt_20.f03 : New test.
    * gfortran.dg/pdt_22.f03 : New test.