Roll third_party/externals/swiftshader b6fa949c4539..1f89f58faeb8 (5 commits)
Roll third_party/externals/swiftshader b6fa949c4539..1f89f58faeb8 (5 commits)

https://swiftshader.googlesource.com/SwiftShader.git/+log/b6fa949c4539..1f89f58faeb8

git log b6fa949c4539..1f89f58faeb8 --date=short --no-merges --format='%ad %ae %s'
2019-09-20 jmadill@chromium.org Do not call Scheduler destructor in libVulkan.
2019-09-20 natsu@google.com [android] Add missing lib to _common_debug target
2019-09-20 nicolascapens@google.com Merge changes Ia7ee9d37,Ia3214243
2019-09-20 sugoi@google.com Enable sampling a depth-stencil format
2019-09-20 sugoi@google.com Fix support for OpKill as non-terminator

Created with:
  gclient setdep -r third_party/externals/swiftshader@1f89f58faeb8

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/swiftshader-skia-autoroll
Please CC bungeman@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=skia.primary:Test-Debian9-Clang-GCE-GPU-SwiftShader-x86_64-Debug-All-SwiftShader
Bug: None
TBR=bungeman@google.com
Change-Id: I59850c8b3d73ab04200d47ad5efa211fe8434d22
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/243356
Reviewed-by: skia-autoroll <e034c62197df5622a9c1bef8b3e012f87a0a9840@skia-public.iam.gserviceaccount.com>
Commit-Queue: skia-autoroll <e034c62197df5622a9c1bef8b3e012f87a0a9840@skia-public.iam.gserviceaccount.com>

google/skia,HalCanary/skia-hc,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,HalCanary/skia-hc,HalCanary/skia-hc,HalCanary/skia-hc,HalCanary/skia-hc,aosp-mirror/platform_external_skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,google/skia,google/skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,google/skia,google/skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,HalCanary/skia-hc