The documentation of loadFile() says:
///\brief Loads header file or shared library.Indeed auto const cr = dc->loadFile("libsc.a", false); results in
/a/lnn51f2/vol/lnn51f2v7/u_t1402742371/andrase/jit/libsc.a:1:1: error: expected unqualified-id
!
^
/a/lnn51f2/vol/lnn51f2v7/u_t1402742371/andrase/jit/libsc.a:3:1: warning: null character ignored [-Wnull-character]
^
…
/a/lnn51f2/vol/lnn51f2v7/u_t1402742371/andrase/jit/libsc.a:7:664: error: source file is not valid UTF-8
…<U+000F>
^
which suggests that cling is trying to load the file as source code instead of as a static library. I think Fail to load shared library in Cling<Windows> is about the same problem (although on windows).