bug#10015: Guile-2.0.3: test-ffi fails

[Hans Aberg]

With guile-2.0.3, OS X 10.7.2, Xcode 4.2, i686-apple-darwin11-llvm-gcc-4.2 
(GCC) 4.2.1, 'make check' fails on test-ffi. Here, libffi-3.0.9 is used; 
libffi-3.0.10 does not compile with the same setup.

Hans