[OCaml] [cmake] Use LLVM_LIBRARY_DIR instead of LLVM_LIBRARY_OUTPUT_INTDIR.

The latter variable is internal.

Original patch by Ramkumar Ramachandra <artagnon@gmail.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224977 91177308-0d34-0410-b5e6-96231b3b80d8
[lit] Make config.llvm_lib_dir available on cmake, too.

The OCaml tests require config.llvm_lib_dir to determine
the OCaml package search path.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224978 91177308-0d34-0410-b5e6-96231b3b80d8
[OCaml] Fix bitrot in tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224979 91177308-0d34-0410-b5e6-96231b3b80d8