How to rebuild stage 1?

[Paolo Bonzini]

> (But let's give Paolo some time to address the technical issues first;
> we are still in stage 1, so only developers, packagers, and brave testers
> are supposed to use what is going to become GCC 4.2. ;-)

Also the reason why I've been collecting issues so far, instead of 
posting all patches for approval, is that you can still use 
--disable-bootstrap to get the old scheme.

Paolo