[Bug bootstrap/54304] linking stage picks up system mpfr instead of in-tree version

[tobi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54304

--- Comment #5 from Tobias Schlüter <tobi at gcc dot gnu.org> 2012-08-17 
19:31:37 UTC ---
It seems I have them in /usr/lib and in /opt/local/lib.  How can I find out
which one it picks up?