glsl: always copy bindless sampler packing constructors to a temp
Closes: mesa/mesa#11648 Fixes: 3cdcc5f0 ("glsl: implement ARB_bindless_texture conversions") Reviewed-by:Marek Olšák <marek.olsak@amd.com> Part-of: <mesa/mesa!30586> (cherry picked from commit 3da4b5ea)