[Ada] multilib patch take three

[Paolo Bonzini]

>> I volunteer to check if there is support for 
>> --enable-multilib=libstdc++-v3,libjava and if not add it. Unfortunately, 
>> --disable-multilib=ada cannot work (because --disable-xxx is the same as 
>> --enable-multilib=no).
> 
> Does that mean that libgcc is implicitely multilibed if --enable-multilib=
> is used ?

No, I just meant "adding a parameter to --enable-multilib to specify 
what to multilib".

>> As an alternative, people that don't want multilibbed libada can not use 
>> libada altogether.  More on this in a second.
> 
> Still not clear to me what you mean here.

I was thinking about using --disable-libada and instead using the "make 
-C gcc gnatlib" target.  You will get no multilibs but I'm not 
up-to-date as to how you build the tools without libada nowadays.

Paolo