Roll SwiftShader from 7a519d34f57a to 31cc1f148e42 (5 revisions)

https://swiftshader.googlesource.com/SwiftShader.git/+log/7a519d34f57a..31cc1f148e42

2020-12-11 capn@google.com Fix typo in 'maxPos' constant vector
2020-12-11 capn@google.com Disable SPIR-V validation during pipeline compilation
2020-12-11 capn@google.com Remove support for R16G16B16 and R32G32B32 sampling
2020-12-11 capn@google.com Enable sampling and filtering of 16-bit SNORM formats
2020-12-11 nicolascapens@google.com Enable sampling and filtering of 16-bit UNORM formats

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/swiftshader-chromium-autoroll
Please CC swiftshader-team+autoroll@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/master/autoroll/README.md

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_chromium_msan_rel_ng;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel;luci.chromium.try:linux-swangle-try-x64;luci.chromium.try:win-swangle-try-x86
Bug: None
Tbr: swiftshader-team+autoroll@google.com
Change-Id: Ie1016858790bee726cc52d85cb8b9b7dcb26b8c7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2586530Reviewed-by: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#836254}

DEPS

@@ -215,7 +215,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling SwiftShader
   # and whatever else without interference from each other.
-  'swiftshader_revision': '7a519d34f57a02c4d87d9825127516d392fda373',
+  'swiftshader_revision': '31cc1f148e429a812538ef863da95f9f0d261680',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling PDFium
   # and whatever else without interference from each other.