improve mllib/word.ml's [wrap] function
improve mllib/word.ml's [wrap] function

improves mailbench throughput from 17 msgs/sec to 26 msgs/sec

mit-pdos/fscq-impl,mit-pdos/fscq-impl,mit-pdos/fscq-impl,mit-pdos/fscq-impl,mit-pdos/fscq-impl