Roll SPIRV-Tools from 52a5f074e9bb to a7112d544b2e (3 revisions)

https://chromium.googlesource.com/external/github.com/KhronosGroup/SPIRV-Tools.git/+log/52a5f074e9bb..a7112d544b2e

2020-06-16 ehsannas@gmail.com Eliminate branches with condition of OpConstantNull (#3438)
2020-06-16 andreperezmaselco.developer@gmail.com spirv-fuzz: Implement vector shuffle fuzzer pass (#3412)
2020-06-16 andreperezmaselco.developer@gmail.com spirv-fuzz: Add replace linear algebra instruction transformation (#3402)

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/spirv-tools-chromium-autoroll
Please CC radial-bots+chrome-roll@google.com,courtneygo@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_angle_vk32_deqp_rel_ng;luci.chromium.try:android_angle_vk32_rel_ng;luci.chromium.try:android_angle_vk64_deqp_rel_ng;luci.chromium.try:android_angle_vk64_rel_ng;luci.chromium.try:linux_angle_deqp_rel_ng;luci.chromium.try:linux-angle-rel;luci.chromium.try:win-angle-rel-32;luci.chromium.try:win-angle-rel-64;luci.chromium.try:win-angle-deqp-rel-32;luci.chromium.try:win-angle-deqp-rel-64
Tbr: radial-bots+chrome-roll@google.com,courtneygo@google.com
Change-Id: Ib61b7166ea285d1453ed44c131afd887b2eea6cf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2249625Reviewed-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@{#779240}

DEPS

@@ -289,7 +289,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.
-  'spv_tools_revision': '52a5f074e9bb6712487653cf360771e98a1ebe97',
+  'spv_tools_revision': 'a7112d544b2ecb20be58e17a9d4397784bb094cb',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.