we can't grow _cv_ variables by using a backticked expr that refers back

we can't grow _cv_ variables by using a backticked expr that refers back

Fri Dec 29 14:53:18 2000  Tim Janik  <timj@gtk.org>

        * configure.in: we can't grow _cv_ variables by using a backticked
        expr that refers back to the variable (glib_cv_sizeof_system_thread for
        G_THREAD_USE_PID_SURROGATE), that'd keep the variable growing every time
        it's evaluated. quantum states, anyone?)