Roll src/third_party/swiftshader 7b1ae2b1188f..5470988c4033 (2 commits)

https://swiftshader.googlesource.com/SwiftShader.git/+log/7b1ae2b1188f..5470988c4033

git log 7b1ae2b1188f..5470988c4033 --date=short --first-parent --format='%ad %ae %s'
2020-04-16 bclayton@google.com CMakeLists: Enabled more clang warnings.
2020-04-16 bclayton@google.com Device/Blitter: Initialize filter3D fields

Created with:
  gclient setdep -r src/third_party/swiftshader@5470988c4033

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/+/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: I49c55e334b91759b93bb767fef1c5b4eea4c80a8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2153641Reviewed-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@{#759856}

DEPS

@@ -191,7 +191,7 @@ 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': '7b1ae2b1188f5bd06f7cebb8a4017027158980a4',
+  'swiftshader_revision': '5470988c40331b8a43a9c4d780fc1b6565a3f62d',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling PDFium
   # and whatever else without interference from each other.