comment on random tests

git-svn-id: https://svn.r-project.org/R/trunk@66881 00db46b3-68df-0310-9c12-caf00c1e9a41
some coding style improvements

git-svn-id: https://svn.r-project.org/R/trunk@66883 00db46b3-68df-0310-9c12-caf00c1e9a41