3918 "pargs -l" dies on incomplete core dumps
3919 mdb/pmap should show unresolved map names on core dumps
3920 executable mapping in core dump misreported when file isn't found
3921 Pfindexec() finds wrong binary, wreaking havoc
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Approved by: Dan McDonald <danmcd@nexenta.com>