Don't raise errors for null pointer objects.
Don't raise errors for null pointer objects.

This changes the pointer target checking to only raise a runtime error if there is a non-null, invalid pointer target. This prevents raising false positives in situations where we just don't track pointer information correctly. In these situations we will still raise errors for accesses to uninitialized memory, which will have to suffice until the pointer target tracking is more thorough.

mheinsen/seec,mheinsen/seec,seec-team/seec,seec-team/seec,seec-team/seec,seec-team/seec,mheinsen/seec,seec-team/seec,mheinsen/seec,mheinsen/seec