RFA: Fix detecting of in-tree MPFR 3.1.0 sources

[Paolo Bonzini]

Il 09/05/2012 15:57, Richard Guenther ha scritto:
>>> >> Btw, it would probably be better to make the drop-in compiles doing
>>> >> a staged install during build instead of using the build tree for use.
>> >
>> > Same for GCC while building target library, but not really easy to do...
>> >
>> > GMP/MPFR are compiled without shared libraries which makes it simpler,
>> > but it would also be a bit ad hoc.
> 
> Sure - but support for dropping in support libraries into the bootstrap tree
> is ad-hoc, too ...

Yes, but pretty much confined in configure.ac.  What I'm wary of is
adding ad-hoc stuff to the Makefile, which is already enough of a mess...

Paolo