Roll third_party/externals/swiftshader cda0cf9d8112..ddcbdc51f2aa (1 commits)

https://swiftshader.googlesource.com/SwiftShader.git/+log/cda0cf9d8112..ddcbdc51f2aa


git log cda0cf9d8112..ddcbdc51f2aa --date=short --no-merges --format='%ad %ae %s'
2019-01-30 chrisforbes@google.com Add SPIRV-Headers as git subtree


Created with:
  gclient setdep -r third_party/externals/swiftshader@ddcbdc51f2aa

The AutoRoll server is located here: https://autoroll.skia.org/r/swiftshader-skia-autoroll

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

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.

CQ_INCLUDE_TRYBOTS=skia.primary:Test-Debian9-Clang-GCE-GPU-SwiftShader-x86_64-Debug-All-SwiftShader
TBR=borenet@google.com

Change-Id: I13c023956b958094c8bc66a5f4a630e524cf0cf9
Reviewed-on: https://skia-review.googlesource.com/c/188072
Reviewed-by: skia-autoroll <skia-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: skia-autoroll <skia-autoroll@skia-public.iam.gserviceaccount.com>