fix memory leak in SAT solver exposed by regression tests

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/sat/sat_clause.cpp

@@ -169,6 +169,7 @@ namespace sat {
 #endif
         void * mem = m_allocator.allocate(size);
         clause * cls = new (mem) clause(m_id_gen.mk(), num_lits, lits, learned);
+        TRACE("sat", tout << "alloc: " << cls->id() << " " << cls << " " << *cls << " " << (learned?"l":"a") << "\n";);
         SASSERT(!learned || cls->is_learned());
         return cls;
     }