[glib] (17 commits) Non-fast-forward update to branch param-speedups2

[Matthias Clasen <matthiasc src gnome org>]

The branch 'param-speedups2' 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:

  46a476c... param: Add a value_is_valid vfunc
  ebec362... param: Add g_param_value_is_valid
  c465445... Add tests for g_param_value_is_valid
  922294b... gobject: Use value_is_valid

Commits added to the branch:

  ad3c339... Add another Unicode testcase (*)
  608eb52... Merge branch 'nonchar-testcase2' into 'main' (*)
  c492f4a... gtype: small optimization (*)
  8f9c509... docs: Use G_PARAM_STATIC_STRINGS in examples and explain it (*)
  3c14b68... docs: Standardise property ID enums in examples (*)
  4173d44... Merge branch 'static-param-strings-docs' into 'main' (*)
  91dafa8... param: Avoid strcmps (*)
  51215bf... param: Avoid strchrs (*)
  5570094... param: Drop a pointless function (*)
  22f51b8... gtype: Speed up g_type_is_a (*)
  e80d2bc... Add a test for g_type_is_a (*)
  1f42078... Merge branch 'param-speedups' into 'main' (*)
  0a3a089... Merge branch 'gtype-speedups' into 'main' (*)
  9725b5a... param: Add a value_is_valid vfunc
  4af7b05... param: Add g_param_value_is_valid
  d113b31... Add tests for g_param_value_is_valid
  f3cc9a1... gobject: Use value_is_valid

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