llvm: handle libdir in llvm-config

The llvm-config wrapper also needs to override a --libdir switch,
otherwise software (like mesa) end up using TMPDIR-based directory for
Clang resource lookup (and also encoding TMPDIR into the target binary).

(From OE-Core rev: c804ef9516d840e9bef717b6add77783a21a443a)

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/llvm/llvm/llvm-config

@@ -35,6 +35,9 @@ for arg in "$@"; do
     --libs)
       output="${output} -lLLVM"
       ;;
+    --libdir)
+      output="${output} ${libdir}"
+      ;;
     --link-shared)
       break
       ;;