Update clang linux to release_40

Bug: skia:
Change-Id: Ibe2406592024a4eb20b278ad189d3abddec129d9
Reviewed-on: https://skia-review.googlesource.com/11285
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>
3 files changed