brw_lower_logical_sends can just check for the TEX_LOGICAL_SRC_SHADOW_C
source; we don't need a generic instruction bit for this. We used to
have one because this was handled in the generator for older hardware
before the advent of logical opcode lowering.
Reviewed-by: Caio Oliveira <caio.oliveira@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33297>
