normalizer for machine ints: support v, add, mul, unsigned div/mod
normalizer for machine ints: support v, add, mul, unsigned div/mod

With @nikswamy

From f3c8eca245578cd8d864ace25da22cfba67bba91 except that we dropped
support for signed div/mod

A-Manning/FStar,FStarLang/FStar,FStarLang/FStar,FStarLang/FStar,A-Manning/FStar,A-Manning/FStar