Fix PR#15468, rbind and cbind with lists.

git-svn-id: https://svn.r-project.org/R/trunk@63983 00db46b3-68df-0310-9c12-caf00c1e9a41
Link to dev.control (PR#15472)

git-svn-id: https://svn.r-project.org/R/trunk@63984 00db46b3-68df-0310-9c12-caf00c1e9a41
correct attribution

git-svn-id: https://svn.r-project.org/R/trunk@63985 00db46b3-68df-0310-9c12-caf00c1e9a41