This test-case is the tzfile for Asuncion generated by
tzlib-2021e as follows, using the tzlib-2021e zic: "zic -d
DEST -r @1546300800 -L /dev/null -b slim
SOURCE/southamerica". Note that in its type 2 header, it
has two entries in its "time-types" array (types), but only
one entry in its "transition types" array (type_idxs).
* timezone/Makefile, timezone/tst-pr28707.c,
timezone/testdata/gen-XT5.sh: New test.
Co-authored-by: Christopher Wong <Christopher.Wong@axis.com>
