boost: Add "container" library (#14878)
boost: Add "container" library (#14878)

"container" is partly a misnomer, as it's realy
the extended allocators part of container.

But every part calls it container, so we do too.
LLNL/spack,iulian787/spack,iulian787/spack,iulian787/spack,LLNL/spack,LLNL/spack,LLNL/spack,iulian787/spack,LLNL/spack,iulian787/spack