The llvm-gcc binaries I downloaded for the 2.7 prerelease contained a
.la for libstdc++, and a .a file, but no .so file:
While testing libtool's new LTO support  everything broke when it
tried to use that .la file, with millions of messages like this:
requires unsupported dynamic reloc; recompile with -fPIC
The problem is that there is no libstdc++.so shipped in llvm-gcc, but
there is a .la and a .a file.
It tries to use the .a file, buts its non-PIC.
So I had to remove the .la and .a file, and put a symlink to the
(simply removing the files was not enough: -lstdc++ was not found,
simply putting the symlink wasn't enough either since the .a was picked
I think its a mistake in the binary package: the .la and .a shouldn't be
shipped, and the .so should be built & shipped!