lib/mkmf.rb: sort list of object files in generated Makefile

Without sorting the list explicitely, its order is indeterministic,
because readdir() is also not deterministic.
When the list of object files varies between builds, they are linked
in a different order, which results in an unreproducible build.

Signed-off-by: Antonio Terceiro <terceiro@debian.org>
Signed-off-by: Reiner Herrmann <reiner@reiner-h.de>
Gbp-Pq: Name 0002-lib-mkmf.rb-sort-list-of-object-files-in-generated-M.patch

rdoc: build reproducible documentation

- sort input filenames
- provide a fixed timestamp to the gzip compression

Signed-off-by: Antonio Terceiro <terceiro@debian.org>
Signed-off-by: Christian Hofstaedtler <zeha@debian.org>
Gbp-Pq: Name 0001-rdoc-build-reproducible-documentation.patch

ruby2.5 (2.5.0-4+rpi1) buster-staging; urgency=medium

  * Disable testsuite.

[dgit import unpatched ruby2.5 2.5.0-4+rpi1]

Import ruby2.5_2.5.0-4+rpi1.debian.tar.xz

[dgit import tarball ruby2.5 2.5.0-4+rpi1 ruby2.5_2.5.0-4+rpi1.debian.tar.xz]

Import ruby2.5_2.5.0.orig.tar.gz

[dgit import orig ruby2.5_2.5.0.orig.tar.gz]