Newer versions of clang are warning about all of these

Change-Id: I73a54ab653a741f9b8a7fb5e11ccd7d83069b966
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/29972Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Presubmit-Ready: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Brian Osman <brianosman@google.com>