The condition to stop iterating so far was to look for load command cmd
field == 0. The iteration would continue past the commands area, and
would finally find lc->cmd ==0, if lucky. Or crash with bus error, if
out of luck.
Correcting this by limiting the number of iterations to the count
specified in mach_header(_64) ncmds field.
rdar://143903403
---------
Co-authored-by: Mariusz Borsa <m_borsa@apple.com>