Join intersection/union of multiple half-spaces when possible.
Join intersection/union of multiple half-spaces when possible.

liangjg/openmc,paulromano/openmc,liangjg/openmc,amandalund/openmc,samuelshaner/openmc,kellyrowland/openmc,paulromano/openmc,bhermanmit/openmc,wbinventor/openmc,mit-crpg/openmc,samuelshaner/openmc,smharper/openmc,walshjon/openmc,wbinventor/openmc,johnnyliu27/openmc,johnnyliu27/openmc,smharper/openmc,mit-crpg/openmc,walshjon/openmc,mit-crpg/openmc,shikhar413/openmc,shikhar413/openmc,paulromano/openmc,samuelshaner/openmc,johnnyliu27/openmc,mit-crpg/openmc,shikhar413/openmc,amandalund/openmc,liangjg/openmc,bhermanmit/openmc,shikhar413/openmc,smharper/openmc,amandalund/openmc,amandalund/openmc,mjlong/openmc,liangjg/openmc,mjlong/openmc,johnnyliu27/openmc,walshjon/openmc,samuelshaner/openmc,smharper/openmc,kellyrowland/openmc,wbinventor/openmc,wbinventor/openmc,paulromano/openmc,walshjon/openmc