Add more checking of newly-allocated pointers
Add more checking of newly-allocated pointers

This adds support for checking that pointers declared to be allocated
by a function are actually allocated, and adds assumptions that the
resulting pointers are valid.
GaloisInc/saw-script,GaloisInc/saw-script,GaloisInc/saw-script,GaloisInc/saw-script,GaloisInc/saw-script