Move is_cfg_cyclic from Body to BasicBlocks

compiler/rustc_mir_dataflow/src/framework/engine.rs

@@ -101,7 +101,7 @@ where
         // transfer function for each block exactly once (assuming that we process blocks in RPO).
         //
         // In this case, there's no need to compute the block transfer functions ahead of time.
-        if !body.is_cfg_cyclic() {
+        if !body.basic_blocks.is_cfg_cyclic() {
             return Self::new(tcx, body, analysis, None);
         }