[heads-up] disabling "../configure --disable-bootstrap && make bootstrap"

[Paolo Bonzini]

As per the subject.  The upcoming merge of toplevel libgcc will only 
work either for disabled bootstrap, or with the toplevel bootstrap 
mechanism.  For this reason, we are now disabling "../configure 
--disable-bootstrap && make bootstrap".  The correct way to bootstrap is 
to just use "./configure" (followed by "make", "make bootstrap" or similar).

Next week, after the merge, the bootstrap rules in the gcc directory 
will go away.

Ciao,

Paolo