Sometimes it takes all day to write a decent comment.  This is one of those times, and I'm still not quite sure I have them correct.
Sometimes it takes all day to write a decent comment.  This is one of those times, and I'm still not quite sure I have them correct.

git-svn-id: 6a9f6578bdee8d959f0ed58970538b4ab6004734@149154 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/libcxxabi,llvm-mirror/libcxxabi,llvm-mirror/libcxxabi,llvm-mirror/libcxxabi,llvm-mirror/libcxxabi