Based on gcc-version.sh, clang-version.sh prints out the correct
version of clang.
Signed-off-by: NSami Tolvanen <samitolvanen@google.com>
Tested-by: NNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>