libxul apps (Firefox, thunderbird) regressed by automatic g_type_init() ctor
@walters
Submitted by Colin Walters Link to original bug (#687763)
Description
First, they definitely emit a warning because they use g_slice_set_config to disable the slice allocator, but the gobject-init_ctor() ends up creating a hash table whch initializes gslice now.
There are also possible indications they dlopen()/dlclose() libgobject, but that would be a separate bug if we find it.
Introduced by https://bugzilla.gnome.org/show_bug.cgi?id=686161