[tree-ssa] problems building fortran

[Richard Earnshaw]

I tried to bootstrap tree-ssa on a netbsdelf system last night and ran 
into a number of problems that I think need addressing before the branch 
can be merged.

1) Fortran relies on an external library package gmp being installed on 
the system.
2) Even when that is installed, it doesn't find it automatically, even 
when it's in a standard place for the OS concerned.
3) And when it is told where the library is, it doesn't link to it 
correctly (no -rpath option), so the executable is unable to locate the 
library at run time.

For other libraries that are needed for a functioning compiler, such as 
zlib, we've pulled these in-tree.  Why are we not doing this for gmp?

R.