zink: fix/improve handling for multi-component bitfield ops
the original improvement for this correctly handled cases where the offset/count values were swizzled with .xxxx, but it was broken for any other swizzling
this adds a nir pass to more easily manipulate the swizzles and rewrite the multi-component ops as multiple ops with the swizzled params
fixes #6697 (closed)
Fixes: 8e97f51c ("zink: handle swizzled offset/count values for shader bitfield ops")