update UBSAN option lists

git-svn-id: https://svn.r-project.org/R/trunk@66273 00db46b3-68df-0310-9c12-caf00c1e9a41
Update info on exec dir.
More on how to include Java code.


git-svn-id: https://svn.r-project.org/R/trunk@66275 00db46b3-68df-0310-9c12-caf00c1e9a41
quick check for sources for Java components

git-svn-id: https://svn.r-project.org/R/trunk@66277 00db46b3-68df-0310-9c12-caf00c1e9a41
add comments

git-svn-id: https://svn.r-project.org/R/trunk@66278 00db46b3-68df-0310-9c12-caf00c1e9a41
more xrefs on finalizers

git-svn-id: https://svn.r-project.org/R/trunk@66279 00db46b3-68df-0310-9c12-caf00c1e9a41