[gobject-introspection] (4 commits) Non-fast-forward update to branch ebassi/compiler-opt

[Emmanuele Bassi <ebassi src gnome org>]

The branch 'ebassi/compiler-opt' 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:

  79ba2c0... Add --compiler argument to g-ir-scanner
  21e7fb9... Document the newly added g-ir-scanner CLI option

Commits added to the branch:

  793b46c... Clean up the subproject rules for GLib (*)
  c691d9f... introspection: Remove 'caller-allocates' from POD types (*)
  5609cc5... Add --compiler argument to g-ir-scanner
  8268f11... Document the newly added g-ir-scanner CLI option

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