[analyzer] Keep tracking the pointer after the escape to more aggressively report mismatched deallocator

Test that the path notes do not change. I don’t think we should print a note on escape.

Also, I’ve removed a check that assumed that the family stored in the RefStete could be
AF_None and added an assert in the constructor.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@179075 91177308-0d34-0410-b5e6-96231b3b80d8