the .DOTLAST primitive by a boolean variable with the same name, this whole
mechanism was broken ... it doesn't save much stat calls but it was wrong.
Thanks to Jason Thorpe for the other shadow-variable fixing patches he
made.
way to get gettimeofday(), etc. On some systems on which you might want
to host make (e.g. solaris), <time.h> won't get you a struct timeval
definition.