Requesting review of PR #6909

[Christopher Chavez]

https://github.com/macports/macports-ports/pull/6909 has been open for
some time, but it has had no feedback from the maintainer nor anyone else.

The PR was initially for having the libpcl port use
compiler.openmp_version instead of a compiler blacklist. However I found
that the port has also been broken since MacPorts updated Boost to 1.70
roughly one year ago (this problem was never reported). This PR now also
fixes the build using a patch posted at the upstream project. The port
is also outdated, however updating it is beyond the effort I intended to
make since I do not use or am familiar with it.

I would say the PR is likely ready to be merged if no one has any
comments or objections.

Christopher A. Chavez