Revert "Emulate the pack/unpack functions for unorms." Causing MSAN failures on Linux. This reverts commit 1915652ee82109d7756dc8349562c3c11ea39b77. Change-Id: Ib23bec16eab22288930be0b41186e54cd8d1f921 Reviewed-on: https://chromium-review.googlesource.com/287127 Reviewed-by: Geoff Lang <geofflang@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>