[analyzer] Fix a CFG printing bug.

Also, add several destructor-related tests. Most of them don't work yet, but it's
good to have them recorded.

Patch by Alex McCarthy!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@205326 91177308-0d34-0410-b5e6-96231b3b80d8