Revert "Update clang_win to yesterday's build (from Chromium)."

This reverts commit cefa808f3f237434139ce5fbbbbaf34cbc90e368.

Reason for revert: Flaky failure: LINK : fatal error LNK1104: cannot open file 'c:\b\s\w\ir\clang_win\lib\clang\6.0.0\lib\windows\clang_rt.ubsan_standalone-x86_64.lib'

Original change's description:
> Update clang_win to yesterday's build (from Chromium).
> 
> Change-Id: Iea0f841f7c9a3449213c549ba310ab2a3d928ca2
> Reviewed-on: https://skia-review.googlesource.com/114093
> Commit-Queue: Ben Wagner <benjaminwagner@google.com>
> Reviewed-by: Mike Klein <mtklein@chromium.org>

TBR=mtklein@chromium.org,mtklein@google.com,benjaminwagner@google.com

Change-Id: I1e738d48f75fbd5878658bc79f3d340dd5acfe0a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/114424
Commit-Queue: Ben Wagner <benjaminwagner@google.com>
Reviewed-by: Ben Wagner <benjaminwagner@google.com>
3 files changed