Do not allow constant factoring during PRAGMA integrity_check, since the

Do not allow constant factoring during PRAGMA integrity_check, since the
constants might be stored in registers that are later reused for other
purposes.  dbsqlfuzz dc9ab26037cf5ef797d28cd1ae0855ade584216d.  Problem
discovered by a new assert() statement added in [6f8b97f31a4c8552].

FossilOrigin-Name: 0bba27b78112b2b2271e498f41c437df985aa2faab302ee5b29d9b60003a8379