~2% faster predictor #10 for NEON
~2% faster predictor #10 for NEON

Change-Id: Icd9cff90c227d702c3ba319131996c5475094520

webmproject/libwebp,webmproject/libwebp,PKRoma/libwebp,PKRoma/libwebp,webmproject/libwebp,PKRoma/libwebp,PKRoma/libwebp,webmproject/libwebp,webmproject/libwebp,PKRoma/libwebp,PKRoma/libwebp