main-loop: Disable GLOBAL_STATE_CODE() assertions

main-loop: Disable GLOBAL_STATE_CODE() assertions

These assertions are very useful for developers to find bugs, and so
they have indeed pointed us towards bugs already.  For users, it is not
so useful to find these bugs.  We should probably not enable them in
releases until we are sufficiently certain that they will not fire
during normal operation, unless something is going seriously wrong.

For example, we have received a bug report that you cannot add an NBD
server on a BDS in an I/O thread with `-incoming defer`.  I am sure this
is a real bug that needs investigation, but we do not really have that
time right now, so close to release, and so I would rather disable the
assertions to get time to investigate such reports.

(I am just putting the link as "buglink" below, not "closes", because
disabling the assertion will not fix the likely underlying bug.)

Buglink: https://gitlab.com/qemu-project/qemu/-/issues/945
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220329093545.52114-1-hreitz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>