UPSTREAM: intel/compiler: Delete unused Gfx8+ code in brw_find_live_channel()

We now handle this in fs_visitor::lower_find_live_channel().

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17530>

(cherry picked from commit 9afd9553530ed4add455e07f74d92b12018b02b3)

BUG=b:209516965
TEST=Cyberpunk no longer hangs

Change-Id: I8bbf3d082c813dab7139b9b5f464072b03f9935a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/mesa/+/3867386
Auto-Submit: Renato Pereyra <renatopereyra@google.com>
Commit-Queue: Ilja Friedel <ihf@chromium.org>
Tested-by: Renato Pereyra <renatopereyra@google.com>
Reviewed-by: Sean Paul <sean@poorly.run>
Reviewed-by: Ilja Friedel <ihf@chromium.org>
4 files changed