Makefile change to restart bootstraps

[Richard Kenner]

    It is, as long as no source file has changed.  Actually, I've got very
    fond of this feature; it helps on many of the platforms to which I've
    got access.  I'd rather not see it dropped.

    When I'm hunting I bug, I don't bootstrap all the time; I often just
    `make' and check that the fix appears to work before going for a full
    bootstrap.  If I had already bootstrapped that tree, I notice that
    bootstrap completes immediately and remember to remove the stamp
    files.

I'm sorry, but I don't follow the scenario you are talking about.
Can you be very precise?