[libglnx] (10 commits) Non-fast-forward update to branch wip/smcv/2-74-constants

[Simon McVittie <smcv src gnome org>]

The branch 'wip/smcv/2-74-constants' 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:

  32e3820... backports: Backport new NONE/DEFAULT constants from GLib 2.

Commits added to the branch:

  af02572... build: Reduce default warning level from 3 to 2 (*)
  c5e1b29... backports: Backport g_info() (*)
  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 (*)
  f780507... Merge branch 'wip/smcv/warnings' into 'master' (*)
  5e07281... Merge branch 'wip/smcv/easy-constants' into 'master' (*)
  0b5d4a0... Merge branch 'wip/smcv/g-info' into 'master' (*)
  2e46d5b... Merge branch 'wip/smcv/testing-helpers' into 'master' (*)
  5bb5b7c... backports: Backport new NONE/DEFAULT constants from GLib 2.

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