Enhanced IsReinterpreted() (RegionStore.cpp) to reason about higher-order

pointers.

Enhanced RegionStoreManager::Retrieve() to handle automatic casts when the
loaded value is different from the requested value. This should be refined over
time, but essentially we should always symbolicate locations as locations, and
convert them to non-locations on demand.

These changes now cause 'misc-ps.m' to pass again.

llvm-svn: 76497