On rawhide, gcc is new enough to output new DWARF information that
pdwtags has not yet learned, but the resulting 'make check' output
was rather confusing:

$ make -C src check
...
  GEN    virkeepaliveprotocol-structs
die__process_function: DW_TAG_INVALID (0x4109) @ <0x58c> not handled!
WARNING: your pdwtags program is too old
WARNING: skipping the virkeepaliveprotocol-structs test
WARNING: install dwarves-1.3 or newer
...
$ pdwtags --version
v1.9

I've filed the pdwtags deficiency as
https://bugzilla.redhat.com/show_bug.cgi?id=772358

* src/Makefile.am (PDWTAGS): Don't leave -t file behind on version
mismatch.  Soften warning message, since 1.9 is newer than 1.3.
Don't leak stderr from broken version.