Fix Clang warning in dEQP-KHR tests. Due to complex and slow process of upstreaming it's easier to disable this warning than to fix it upstream. Only happens in a Chromium build because Chromium uses a specialized standard library. Bug: angleproject:3353 Change-Id: I01607a00e469110c87458458d3b205fd59ea3db3 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1614426 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com> Reviewed-by: Yuly Novikov <ynovikov@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>