PropertyTable supports C++ iteration by offering begin() and end() methods, and an iterator class.  The begin() methods and the iterator operator++() method uses PropertyTable::skipDeletedEntries() to skip over deleted entries in the table.  However, PropertyTable::skipDeletedEntries() does not prevent the iteration pointer from being incremented past the end of the table.  As a result, we can iterate past the end of the table.  Note that the C++ iteration protocol tests for the iterator not being equal to the end() value.  It does not do a <= test.  If the iterator ever shoots past end, the loop will effectively not terminate.

This issue can manifest if and only if the last entry in the table is a deleted one.

<rdar://problem/41282849>