allow gcd when dio ignores some terms

Signed-off-by: Lev Nachmanson <[email protected]>

Author: levnach

src/math/lp/int_solver.cpp

@@ -223,7 +223,7 @@ namespace lp {
 
             lia_move r = lia_move::undef;
 
-            if (m_gcd.should_apply())
+            if (m_gcd.should_apply() || (settings().dio() && m_dio.some_terms_are_ignored()))
                 r = m_gcd();
 
             check_return_helper pc(lra);