[MLIR] Add more logging to DenseAnalysis/DeaDCodeAnalysis/TestDenseBackwardDataFlowAnalysis (NFC) (llvm#161503)

Just some more debugging help here, it may need more tweaking in the future.

Author: joker-eph

mlir/lib/Analysis/DataFlow/DeadCodeAnalysis.cpp

@@ -522,14 +522,14 @@ void DeadCodeAnalysis::visitRegionBranchEdges(
     // Mark the entry block as executable.
     auto *state = getOrCreate<Executable>(point);
     propagateIfChanged(state, state->setToLive());
-    LDBG() << "Marked region successor live: " << point;
+    LDBG() << "Marked region successor live: " << *point;
 
     // Add the parent op as a predecessor.
     auto *predecessors = getOrCreate<PredecessorState>(point);
     propagateIfChanged(
         predecessors,
         predecessors->join(predecessorOp, successor.getSuccessorInputs()));
-    LDBG() << "Added region branch as predecessor for successor: " << point;
+    LDBG() << "Added region branch as predecessor for successor: " << *point;
   }
 }