Make modesetting dynamically bind the glamor/shadow API
Pull these out from dlsym iff we load the appropriate module. This allows the modesetting driver to be linked with ld -z now. This should be the last change needed for #692 (closed).
Pull these out from dlsym iff we load the appropriate module. This allows the modesetting driver to be linked with ld -z now. This should be the last change needed for #692 (closed).