CGAL wmake sets incorrect paths to MPFR and GMP
Filed by @sergiykhan - re-located from ThirdParty (https://develop.openfoam.com/Development/ThirdParty-plus/issues/4)
When compiling OpenFOAM v1606, the ./makeGcc script gets the MPFR and GMP libraries placed in the lib64 sub-directory, while $WM_PROJECT_DIR/wmake/rules/CGAL
sets paths explicitly to lib.