Prevent ICE on gfortran 4.8
Prevent ICE on gfortran 4.8

liangjg/openmc,shikhar413/openmc,johnnyliu27/openmc,liangjg/openmc,amandalund/openmc,walshjon/openmc,paulromano/openmc,smharper/openmc,smharper/openmc,johnnyliu27/openmc,johnnyliu27/openmc,shikhar413/openmc,mit-crpg/openmc,paulromano/openmc,mit-crpg/openmc,walshjon/openmc,walshjon/openmc,amandalund/openmc,smharper/openmc,shikhar413/openmc,mit-crpg/openmc,liangjg/openmc,wbinventor/openmc,wbinventor/openmc,paulromano/openmc,amandalund/openmc,johnnyliu27/openmc,mit-crpg/openmc,walshjon/openmc,amandalund/openmc,shikhar413/openmc,wbinventor/openmc,liangjg/openmc,smharper/openmc,paulromano/openmc,wbinventor/openmc