- the internal data are contiguous so can broadcast size and internals
directly without an intermediate stream.
ENH: split out broadcast time for profilingPstream information
STYLE: minor Pstream cleanup
- UPstream::commsType_ from protected to private, since it already has
inlined noexcept getters/setters that should be used.
- don't pass unused/unneed tag into low-level MPI reduction templates.
Document where tags are not needed
- had Pstream::broadcast instead of UPstream::broadcast in internals
