msmc2: added package at v2.1.2 (#17170)
msmc2: added package at v2.1.2 (#17170)

Co-authored-by: Adam J. Stewart <023e75a89b1f5ca1e59909f8756c185885836ad9@gmail.com>
LLNL/spack,iulian787/spack,iulian787/spack,iulian787/spack,iulian787/spack,LLNL/spack,LLNL/spack,LLNL/spack,LLNL/spack,iulian787/spack