We now don't break the strict aliasing rules.
Also, having a compiler flag that disables a warning among the flags that are
meant to add extra sanity checking is not correct either:
--enable-extra-warnings=no would generate a bad aliasin warning while
the --enable-extra-warnings=yes would not.
GValueArray is deprecated since GLib 2.31.14, but we need to use it for
dbus-glib based code.
We should re-enable deprecation warnings once we switch to GDBus.