[libglnx] (8 commits) Non-fast-forward update to branch wip/smcv/testing-helpers

[Simon McVittie <smcv src gnome org>]

The branch 'wip/smcv/testing-helpers' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  7d599d7... backports: Backport G_SPAWN_DEFAULT
  1e9a2ea... backports: Backport G_OPTION_FLAG_NONE, G_OPTION_ENTRY_NULL
  ba51dc2... backports: Backport G_DBUS_METHOD_INVOCATION_HANDLED, _UNHA
  fe50ebb... testlib: Be compatible with ancient GLib by using glnx_clos
  a88d13b... Move assertion/test utilities to a separate header
  247bf07... Backport most of the test convenience helpers from GLib's G

Commits added to the branch:

  7a2f26a... fdio: fix fd offset handling with `FICLONE` (*)
  26375b5... Merge branch 'pr/ficlone-fixes' into 'master' (*)
  fabcdb3... backports: Backport G_SPAWN_DEFAULT (*)
  b565872... backports: Backport G_OPTION_FLAG_NONE, G_OPTION_ENTRY_NULL (*)
  29681b4... backports: Backport G_DBUS_METHOD_INVOCATION_HANDLED, _UNHA (*)
  9a0e6fd... testlib: Be compatible with ancient GLib by using glnx_clos
  5a60c0b... Move assertion/test utilities to a separate header
  c52b73d... Backport most of the test convenience helpers from GLib's G

(*) This commit already existed in another branch; no separate mail sent