glsl: fix shader cache for packed param list

Some types of params such as some builtins are always padded. We
need to keep track of this so we can restore the list correctly.

Here we also remove a couple of cache entries that are not actually
required as they get rebuilt by the _mesa_add_parameter() calls.

This patch fixes a bunch of arb_texture_multisample and
arb_sample_shading piglit tests for the radeonsi NIR backend.

Fixes: edded123 ("mesa: rework ParameterList to allow packing")

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
(cherry picked from commit 7536af67)