Add __declspec(safebuffers) to functions with arrays on stack that have explicit checks to avoid a redundent compiler stack check.
BUG=none
TEST=unitests pass
R=ryanpetrie@google.com

Review URL: https://webrtc-codereview.appspot.com/3289004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@837 16f28f9a-4ce2-e073-06de-1de4eb20be90