Roll SwiftShader 4d3efed..8aa0768

https://swiftshader.googlesource.com/SwiftShader.git/+log/4d3efed..8aa0768

BUG=

TBR=kbr@chromium.org

TEST=bots

CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel,linux_chromium_cfi_rel_ng;master.tryserver.chromium.android:android_optional_gpu_tests_rel

Change-Id: I1f88e9213f4387e38b4b9d1059d7ee9a419d755f
Reviewed-on: https://chromium-review.googlesource.com/599015Reviewed-by: Alexis Hétu <sugoi@chromium.org>
Commit-Queue: Alexis Hétu <sugoi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491572}

DEPS

@@ -60,7 +60,7 @@ 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': '4d3efedb10ce60bdb7847336eba0360fdc9af9d3',
+  'swiftshader_revision': '8aa07683f555dd02e2c7cae2d3e28c53385cc504',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling PDFium
   # and whatever else without interference from each other.