Fix clang++ warnings on -Wtautological-constant-out-of-range-compare

src/objects.h

 // 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.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 5721 matching lines @@
   inline bool is_observed() {
     return ((1 << kIsObserved) & bit_field()) != 0;
   }
 
   inline void set_is_extensible(bool value);
   inline bool is_extensible();
   inline void set_is_prototype_map(bool value);
   inline bool is_prototype_map();
 
   inline void set_elements_kind(ElementsKind elements_kind) {
-    DCHECK(elements_kind < kElementsKindCount);
+    DCHECK(static_cast<int>(elements_kind) < kElementsKindCount);
     DCHECK(kElementsKindCount <= (1 << Map::ElementsKindBits::kSize));
     set_bit_field2(Map::ElementsKindBits::update(bit_field2(), elements_kind));
     DCHECK(this->elements_kind() == elements_kind);
   }
 
   inline ElementsKind elements_kind() {
     return Map::ElementsKindBits::decode(bit_field2());
   }
 
   // Tells whether the instance has fast elements that are only Smis.
@@ skipping 5244 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_