mesa-llvmpipe: CP one upstream fix for crashing.

Bug from https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5492
Fixed by https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5821

BUG=chromium:1127052
TEST=Run webgl_conformance_tests (bug comment #34)

Change-Id: Ib1b2fa7f8265fa825fa98aec7fca946fce139faf
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/2416405
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Reviewed-by: Chia-I Wu <olv@google.com>
Tested-by: Lepton Wu <lepton@chromium.org>
Commit-Queue: Lepton Wu <lepton@chromium.org>
Auto-Submit: Lepton Wu <lepton@chromium.org>
3 files changed