On the toplevel configure and build system

[Geoffrey Keating]

"Joseph S. Myers" <joseph@codesourcery.com> writes:

> 2. If you put directories from the GCC repository into your build, you 
> should expect GCC and its libraries to be built; toplevel should not 
> disable GCC on the grounds that GCC does not support a given target.  

I'd appreciate it if creating a combined tree and building it still
worked on/for every target, even those which one or more of GDB, GCC,
newlib, sid, etc., do not support.