external/libvpx: backport GetCoeffs overflow suppression | DO NOT MERGE am: 354408e4dc am: aa5c295832 am: 77b8650c64

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/libvpx/+/10525911

Change-Id: I1c0508049fc1ffc981afe7d0c99b23d26049c184