Patch to find libc++ in the prefix/lib directory

Hi,

I have attached a patch that allowed me to use libc++
installed in the same prefix as I installed clang+llvm
on ubuntu 12.04 . ($HOME/local for example.)

I would be surprised if it is correct :slight_smile: But hopefully
it isn't to hard to fix it up into something usable if someone has
some advice on what would be correct. (Though I will be offline for
a week starting Saturday.)

Thanks,

Joseph

patch.diff (2.47 KB)