[glib] (7 commits) Non-fast-forward update to branch param-speedups

[Matthias Clasen <matthiasc src gnome org>]

The branch 'param-speedups' 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:

  3152177... param: Avoid strcmps
  fdc9870... param: Avoid strchrs
  007f6b2... param: Drop a pointless function
  7b5c5a4... param: Add a value_is_valid vfunc
  8e13b59... gobject: Use value_is_valid

Commits added to the branch:

  c492f4a... gtype: small optimization (*)
  f0e2727... gtype: Speed up g_type_is_a (*)
  f871828... param: Avoid strcmps
  7a9c5f6... param: Avoid strchrs
  ccd4a0c... param: Drop a pointless function
  dff7159... param: Add a value_is_valid vfunc
  f7406b2... gobject: Use value_is_valid

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