[turbofan] Ensure that NTLs are always properly connected to the end.

src/compiler/simplified-lowering.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/simplified-lowering.h"
 
 #include <limits>
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 455 matching lines @@
       case IrOpcode::kStart:
       case IrOpcode::kDead:
         return VisitLeaf(node, 0);
       case IrOpcode::kParameter: {
         // TODO(titzer): use representation from linkage.
         Type* upper = NodeProperties::GetBounds(node).upper;
         ProcessInput(node, 0, 0);
         SetOutput(node, kRepTagged | changer_->TypeFromUpperBound(upper));
         return;
       }
+      case IrOpcode::kAlways:
+        return VisitLeaf(node, kRepBit);
       case IrOpcode::kInt32Constant:
         return VisitLeaf(node, kRepWord32);
       case IrOpcode::kInt64Constant:
         return VisitLeaf(node, kRepWord64);
       case IrOpcode::kFloat64Constant:
         return VisitLeaf(node, kRepFloat64);
       case IrOpcode::kExternalConstant:
         return VisitLeaf(node, kMachPtr);
       case IrOpcode::kNumberConstant:
         return VisitLeaf(node, kRepTagged);
@@ skipping 1027 matching lines @@
 
 void SimplifiedLowering::DoStringLessThanOrEqual(Node* node) {
   node->set_op(machine()->IntLessThanOrEqual());
   node->ReplaceInput(0, StringComparison(node, true));
   node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8