Roll src/third_party/SPIRV-Tools/src f20c0d7971c6..e95fbfb1f509 (7 commits)

https://chromium.googlesource.com/external/github.com/KhronosGroup/SPIRV-Tools.git/+log/f20c0d7971c6..e95fbfb1f509

git log f20c0d7971c6..e95fbfb1f509 --date=short --first-parent --format='%ad %ae %s'
2020-04-02 afdx@google.com spirv-fuzz: Transformation to add OpConstantNull (#3273)
2020-04-02 afdx@google.com spirv-fuzz: Handle isomorphic types property in composite construction (#3262)
2020-04-02 afdx@google.com spirv-fuzz: Limit adding of new variables to 'basic' types (#3257)
2020-04-02 afdx@google.com spirv-fuzz: Only replace regular ids with synonyms (#3255)
2020-04-02 afdx@google.com spirv-fuzz: Introduce TransformationContext (#3272)
2020-04-02 afdx@google.com spirv-fuzz: Add validator options (#3254)
2020-04-02 alanbaker@google.com Update dominates to check for null nodes (#3271)

Created with:
  gclient setdep -r src/third_party/SPIRV-Tools/src@e95fbfb1f509

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,cwallez@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_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
Bug: None
Tbr: radial-bots+chrome-roll@google.com,cwallez@google.com
Change-Id: I50aec0564dc212ec9e0526419805d6f2e237c8a8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2135465Reviewed-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@{#756221}

DEPS

@@ -286,7 +286,7 @@ 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': 'f20c0d7971c6705a99b91d7a0278eabbc5d91195',
+  'spv_tools_revision': 'e95fbfb1f509ad7a7fdfb72ac35fe412d72fc4a4',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.