Print more template parameters with ptype

This bug points out that a template parameter that is a constant is
not printed by 'ptype' -- in fact, only type parameters are displayed.
However, there's no real reason for this, and any template parameter
that the DWARF reader can turn into a symbol should be printable.

Note that some parameters are still missing from the DWARF; see the
kfails in the test for details.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=33670
Reviewed-By: Christina Schimpe <christina.schimpe@intel.com>
Approved-By: Andrew Burgess <aburgess@redhat.com>