Please *bootstrap* patches

[Robert Dewar]

Steven Bosscher wrote:

> So, *please*, can people *bootstrap* their patches, and make sure
> this kind of mistake does not happen again?
> 
> Gr.
> Steven

Of course I agree with Steven that all patches should be bootstrapped
before being submitted, but I just wanted to mention an additional
working practice that we use in the GNAT world that provides an added
precaution, which is that all developers use by default the switches
that the compiler uses for bootstrapping, so all our internal
development of compiler components is always done with the
warnings-are-on-and-fatal flags set. That seems a good working
practice to adopt more generally.