the trailing width % 8 bytes would clear the upper bytes of
alpha_mask as they're done one at a time
since:
49d0280d NEON: implement several alpha-processing functions
Change-Id: Iff76c0af3094597285a6aa6ed032b345f9856aae
similar to '* const', __restrict needs to be included in the
declaration to avoid warnings like:
src\dsp\alpha_processing.c(429): warning C4028: formal parameter 1
different from declaration
this change also moves WEBP_RESTRICT to dsp.h to avoid a circular
dependency between it and utils.h which already includes dsp.h
Change-Id: Ib070d358a372e76fae4be5445ab288940b9baac0
