catch up with R-patched

git-svn-id: https://svn.r-project.org/R/trunk@63001 00db46b3-68df-0310-9c12-caf00c1e9a41
update

git-svn-id: https://svn.r-project.org/R/trunk@63002 00db46b3-68df-0310-9c12-caf00c1e9a41
switch(<factor>, ..) now warns

git-svn-id: https://svn.r-project.org/R/trunk@63004 00db46b3-68df-0310-9c12-caf00c1e9a41