Revert "Roll src/third_party/swiftshader 6c3dc3581eaf..430def835f9f (7 commits)"

This reverts commit 6d035d3a.

Reason for revert: Broke multiple test targets on Linux CFI

Bug:1047150
Original change's description:
> Roll src/third_party/swiftshader 6c3dc3581eaf..430def835f9f (7 commits)
> 
> https://swiftshader.googlesource.com/SwiftShader.git/+log/6c3dc3581eaf..430def835f9f
> 
> git log 6c3dc3581eaf..430def835f9f --date=short --first-parent --format='%ad %ae %s'
> 2020-01-29 capn@google.com Regres: aways use build output path for ICD json
> 2020-01-29 capn@google.com Associate bug IDs with unimplemented functionality
> 2020-01-29 amaiorano@google.com Fix memory leak in rr::Optimizer
> 2020-01-29 bclayton@google.com Regres: Make it work on windows.
> 2020-01-29 amaiorano@google.com Subzero: implement coroutines for Win32
> 2020-01-29 bclayton@google.com SpirvShaderDebugger: Expose builtins in HLSL / GLSL.
> 2020-01-29 bclayton@google.com Vulkan/Debug: Add VariableContainer::extend()
> 
> Created with:
>   gclient setdep -r src/third_party/swiftshader@430def835f9f
> 
> 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
> Bug: None
> Tbr: swiftshader-team+autoroll@google.com
> Change-Id: I02f8c532b33dc934d1f4da0da6eb43dd0b7e174b
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2029219
> Reviewed-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@{#736686}

TBR=chromium-autoroll@skia-public.iam.gserviceaccount.com,swiftshader-team+autoroll@google.com

Change-Id: I6721bde098fb6ed88cdaa210ec1168fb1f01712d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: None
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
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2030174Reviewed-by: Ioana Pandele <ioanap@chromium.org>
Commit-Queue: Ioana Pandele <ioanap@chromium.org>
Cr-Commit-Position: refs/heads/master@{#736806}

DEPS

@@ -193,7 +193,7 @@ 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': '430def835f9f85d52f4a96db9b715cd9a7403c9c',
+  'swiftshader_revision': '6c3dc3581eaf4345c0507d5ac7bb013d55351547',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling PDFium
   # and whatever else without interference from each other.