In the hotdoc inspector for example, pads are instantiated with
g_object_new, other code paths to get/set properties already make
that check.
And update doc cache
* Making sure that `static inline` function are in the GIR (by first
defining them, and make sure to mark as skiped)
* Do not try to link to unexisting symbols
* Also generate GIR information about gst_tracers