Remove these three instructions, as they will be delayed to a later phase due to implementation difficulties noted by @sunfishcode .
horizontalSum
absoluteDifference
widenedAbsoluteDifference
Because these were already mentioned in our Stage 2 proposal, hopefully we will be able to restart them at that later stage once they are worked out.
Remove these three instructions, as they will be delayed to a later phase due to implementation difficulties noted by @sunfishcode .
Remove these from the spec, polyfill and tests.