third_party/clspv: Disable the warnings on build Adding a few cflags options to disable warnings seen while building clspv. Bug: angleproject:8619 Signed-off-by: Gowtham Tammana <g.tammana@samsung.com> Change-Id: Ibee07e75331dad35e52a1937e5f56dfca855ea0c Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5380723 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>