illumos gate

Corresponding with Joyent bugs:

  OS-770 need ::scalehrtime dcmd
    Increasingly in the system, timestamps are being recorded as 
    TSCs (e.g., t_hrtime) – but this leaves them unscaled. Scaling 
    these timestamps manually is a pain in the butt, but doing so
    can be critical for understanding system failure; we need a
    ::scalehrtime dcmd.

  OS-752 ::ugrep and ::kgrep don't work for sizes less than 4
      Running ::kgrep/::ugrep for sizes less than 4 (i.e., 1 or 2) 
      doesn't properly work: it returns many too many hits.

  OS-751 ::umem_verify seg faults on a dump with rampant corruption