Move loop register usage to relative addressing. Bug 22652760 Change-Id: I50c6935bac91f586953b0dd2abd0d2a859468ee1 Reviewed-on: https://swiftshader-review.googlesource.com/4579 Tested-by: Nicolas Capens <capn@google.com> Reviewed-by: Alexis Hétu <sugoi@google.com> Reviewed-by: Nicolas Capens <capn@google.com>