fix PR#15465

git-svn-id: https://svn.r-project.org/R/trunk@63968 00db46b3-68df-0310-9c12-caf00c1e9a41
stress where anti-aliasing is applied to avoid any more non-bug reports

git-svn-id: https://svn.r-project.org/R/trunk@63969 00db46b3-68df-0310-9c12-caf00c1e9a41
record all down viewports as strict vpPaths

git-svn-id: https://svn.r-project.org/R/trunk@63970 00db46b3-68df-0310-9c12-caf00c1e9a41
note on the need for an up-to-date version of OS X.

git-svn-id: https://svn.r-project.org/R/trunk@63971 00db46b3-68df-0310-9c12-caf00c1e9a41