Fix bug in the dominator tree construction algorithm

kernel/modelverse_jit/cfg_dominators.py

@@ -74,7 +74,7 @@ def get_immediate_dominators(entry_point):
                 continue
 
             new_idom = None
-            for pred in predecessor_map[entry_point]:
+            for pred in predecessor_map[block]:
                 if pred not in postorder_nums:
                     continue