[PING]^N Fix ppc64 bootstrap with a -m32 host compiler

[Paolo Bonzini]

>> In general I think you really *want* to have a matching CC_FOR_BUILD and
>> BUILD_LIBIBERTY.  So, if you change the former, arrange that the other
>> matches.  Think of a host compiler which has a different ABI than the
>> built compiler: this is something that is not always expressible with a
>> target triplet.
>>     
> This is absolutely correct.
>   
Phew. :-P
> Now, I'm getting a little confused here for some reason....
> is your patch designed to make things work properly with the scheme you
> just described above (in which case, full speed ahead!), or is your
> patch a different option?
Yes, my patch implements (3) in the other e-mail: in other words, make 
sure that the toplevel gives to the gcc the directory name of 
BUILD_LIBIBERTY.  From my other message:
> in configure-stageN-gcc you can
> pass a --with-build-libsubdir=$(HOST_SUBDIR) option that GCC can use to
> find the BUILD_LIBIBERTY.  The difference is that the knowledge of which
> directory to use, is now in the toplevel rather than in the GCC directory.
Thanks for the useful discussion!

Paolo