[turbofan] Allow ReplaceWithValue to kill control.

src/compiler/verifier.cc

Index: src/compiler/verifier.cc
diff --git a/src/compiler/verifier.cc b/src/compiler/verifier.cc
index 66aeffa2b2b7c42ae2c32172fc6cc5fce0649f8c..59224539e9a3e3627d17cfbebbf11d1707ebd68c 100644
--- a/src/compiler/verifier.cc
+++ b/src/compiler/verifier.cc
@@ -194,7 +194,11 @@ void Verifier::Visitor::Check(Node* node) {
       break;
     case IrOpcode::kDead:
       // Dead is never connected to the graph.
-      UNREACHABLE();
+      // TODO(mstarzinger): Make the GraphReducer immediately perform control
+      // reduction in case control is killed. This will prevent {Dead} from
+      // being reachable after a phase finished. Then re-enable below assert.
+      // UNREACHABLE();
+      break;
     case IrOpcode::kBranch: {
       // Branch uses are IfTrue and IfFalse.
       int count_true = 0, count_false = 0;