Properly handle NULL RHS in VECSUBASSING and friends and handle more
LHS value types, also in VECSUBSET, etc.


git-svn-id: https://svn.r-project.org/R/trunk@66647 00db46b3-68df-0310-9c12-caf00c1e9a41
merge.dendrogram(..., adjust="auto")  and plot.hclust(..., check=TRUE)

git-svn-id: https://svn.r-project.org/R/trunk@66648 00db46b3-68df-0310-9c12-caf00c1e9a41
compute INTEGER(.) only once


git-svn-id: https://svn.r-project.org/R/trunk@66649 00db46b3-68df-0310-9c12-caf00c1e9a41