Roll shaderc from d07e90e7ff54 to 13480cb0ab94 (1 revision)

https://chromium.googlesource.com/external/github.com/google/shaderc/+log/d07e90e7ff54..13480cb0ab94

2020-07-18 bclayton@google.com Mingw - use `posix` toolchain flavor (#1108)

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/shaderc-chromium-autoroll
Please CC radial-bots+chrome-roll@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

Tbr: radial-bots+chrome-roll@google.com
Change-Id: I97d7e70eb70ed371461eac29f31d7f10f917a4e2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2305745Reviewed-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@{#789796}

DEPS

@@ -314,7 +314,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.
-  'shaderc_revision': 'd07e90e7ff543f80a41916cd52b259b279a16611',
+  'shaderc_revision': '13480cb0ab948e00a5a12794bb6d497a43f9b52c',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.