This patch causes problem for multilib: GCCInstallation.getInstallPath() is
empty in that case and 'clang -m32 foo.c' will put a -L with nothing after it
but the .o file generated, effectively dropping it.
With recent freebsd-lib versions, it is only needed for c++ with libstdc++,
which is actually broken because clang++ cannot find the headers. it is fine
with clang++ -stdlib=libc++.
aballier@g.o

diff -upNr a/llvm-3.1.src/tools/clang/lib/Driver/ToolChains.cpp b/llvm-3.1.src/tools/clang/lib/Driver/ToolChains.cpp
--- a/llvm-3.1.src/tools/clang/lib/Driver/ToolChains.cpp	2012-05-24 04:08:48.393073000 -0400
+++ b/llvm-3.1.src/tools/clang/lib/Driver/ToolChains.cpp	2012-05-24 04:11:38.113153421 -0400
@@ -1635,6 +1635,8 @@ FreeBSD::FreeBSD(const Driver &D, const
     getFilePaths().push_back(getDriver().SysRoot + "/usr/lib32");
   else
     getFilePaths().push_back(getDriver().SysRoot + "/usr/lib");
+
+   getFilePaths().push_back(GCCInstallation.getInstallPath());
 }
 
 Tool &FreeBSD::SelectTool(const Compilation &C, const JobAction &JA,