8182710: File.listRoots() always returns the root of CD drive Summary: Include only logical drives with an extant filesystem location Reviewed-by: clanger, rriggs, plevart, tvaleev

^build/
^dist/
^.idea/
nbproject/private/
^webrev
^.src-rev$
^.jib/
.DS_Store
.metadata/
.recommenders/