Introduce {ConstantElementsPair} struct for type safety.

src/objects-debug.cc

 // Copyright 2012 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/objects.h"
 
 #include "src/bootstrapper.h"
 #include "src/disasm.h"
 #include "src/disassembler.h"
 #include "src/field-type.h"
@@ skipping 1090 matching lines @@
   VerifyObjectField(kValue2Offset);
   VerifyObjectField(kValue3Offset);
 }
 
 void ContextExtension::ContextExtensionVerify() {
   CHECK(IsContextExtension());
   VerifyObjectField(kScopeInfoOffset);
   VerifyObjectField(kExtensionOffset);
 }
 
+void ConstantElementsPair::ConstantElementsPairVerify() {
+  CHECK(IsConstantElementsPair());
+  VerifySmiField(kElementsKindOffset);
+  VerifyObjectField(kConstantValuesOffset);
+}
 
 void AccessorInfo::AccessorInfoVerify() {
   CHECK(IsAccessorInfo());
   VerifyPointer(name());
   VerifyPointer(expected_receiver_type());
   VerifyPointer(getter());
   VerifyPointer(setter());
   VerifyPointer(js_getter());
   VerifyPointer(data());
 }
@@ skipping 403 matching lines @@
 
   // Both are done at the same time.
   CHECK_EQ(new_it.done(), old_it.done());
 }
 
 
 #endif  // DEBUG
 
 }  // namespace internal
 }  // namespace v8