Suppress existing warnings.

Bug b/66996870

Change-Id: I9b78f840638a57c2559ccc4dbc583cc6a6e21c14
Reviewed-on: https://swiftshader-review.googlesource.com/17630Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>