[turbofan] more verification of rpo

src/compiler/verifier.cc

Index: src/compiler/verifier.cc
diff --git a/src/compiler/verifier.cc b/src/compiler/verifier.cc
index 23cec7a809794623625823e99d8f0b2688508d6b..972fec41b5dd3bcacf2152a708ec21494e36bb10 100644
--- a/src/compiler/verifier.cc
+++ b/src/compiler/verifier.cc
@@ -304,6 +304,17 @@ void ScheduleVerifier::Run(Schedule* schedule) {
   for (BasicBlockVector::iterator b = rpo_order->begin(); b != rpo_order->end();
        ++b) {
     CHECK_EQ((*b), schedule->GetBlockById((*b)->id()));
+    // All predecessors and successors should be in rpo and in this schedule.
+    BasicBlock::Predecessors p = (*b)->predecessors();
+    for (BasicBlock::Predecessors::iterator j = p.begin(); j != p.end(); ++j) {
+      CHECK_GE((*j)->rpo_number_, 0);
+      CHECK_EQ((*j), schedule->GetBlockById((*j)->id()));
+    }
+    BasicBlock::Successors s = (*b)->successors();
+    for (BasicBlock::Successors::iterator j = s.begin(); j != s.end(); ++j) {
+      CHECK_GE((*j)->rpo_number_, 0);
+      CHECK_EQ((*j), schedule->GetBlockById((*j)->id()));
+    }
   }
 
   // Verify RPO numbers of blocks.