Roll SwiftShader from e1012cfc791d to b638dfe160a1 (5 revisions)

https://swiftshader.googlesource.com/SwiftShader.git/+log/e1012cfc791d..b638dfe160a1

2020-11-11 nicolascapens@google.com Fix backslash interpreted as part of URL
2020-11-11 srisser@google.com Implement VK_KHR_shader_float_controls
2020-11-11 amaiorano@google.com Subzero: clang-format crosstest, pnacl-llvm, runtime, and unittest
2020-11-11 amaiorano@google.com Subzero: clang-format src
2020-11-11 capn@google.com Fix LLVM host triple for ORCv2 JIT

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/+doc/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;luci.chromium.try:linux-swangle-try-x64;luci.chromium.try:win-swangle-try-x86
Bug: None
Tbr: swiftshader-team+autoroll@google.com
Change-Id: I98581d0e2f34f8bdd239fe965ebbd07988fe9c12
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2533502Reviewed-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@{#826606}

DEPS

@@ -213,7 +213,7 @@ 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': 'e1012cfc791ddbc6ce11e319831da7973b9a5b32',
+  'swiftshader_revision': 'b638dfe160a17f288c774fd98f725f212f843c2b',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling PDFium
   # and whatever else without interference from each other.