[csa] Fix the bound & used condition check for RawMachineLabel and CodeAssemblerLabel.

src/compiler/raw-machine-assembler.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/raw-machine-assembler.h"
 
 #include "src/compiler/node-properties.h"
 #include "src/compiler/pipeline.h"
 #include "src/compiler/scheduler.h"
 #include "src/objects-inl.h"
@@ skipping 314 matching lines @@
   return node;
 }
 
 Node* RawMachineAssembler::MakeNode(const Operator* op, int input_count,
                                     Node* const* inputs) {
   // The raw machine assembler nodes do not have effect and control inputs,
   // so we disable checking input counts here.
   return graph()->NewNodeUnchecked(op, input_count, inputs);
 }
 
-RawMachineLabel::~RawMachineLabel() { DCHECK(bound_ || !used_); }
+RawMachineLabel::~RawMachineLabel() {
+  // If this DCHECK fails, it means that the label has been bound but it's not
+  // used, or the opposite. This would cause the register allocator to crash.
+  DCHECK_EQ(bound_, used_);
+}
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8