Wrap generated graphs to ensure entry and exit nodes have no extra edges

Signed-off-by: Danila Fedorin <danila.fedorin@gmail.com>

Language.agda

@@ -55,16 +55,16 @@ record Program : Set where
         rootStmt : Stmt
 
     graph : Graph
-    graph = buildCfg rootStmt
+    graph = wrap (buildCfg rootStmt)
 
     State : Set
     State = Graph.Index graph
 
     initialState : State
-    initialState = proj₁ (buildCfg-input rootStmt)
+    initialState = proj₁ (wrap-input (buildCfg rootStmt))
 
     finalState : State
-    finalState = proj₁ (buildCfg-output rootStmt)
+    finalState = proj₁ (wrap-output (buildCfg rootStmt))
 
     private
         vars-Set : StringSet