Fix a potential overflow of binary search

src/objects-inl.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.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 2766 matching lines @@
 template <SearchMode search_mode, typename T>
 int BinarySearch(T* array, Name* name, int low, int high, int valid_entries,
                  int* out_insertion_index) {
   DCHECK(search_mode == ALL_ENTRIES || out_insertion_index == NULL);
   uint32_t hash = name->Hash();
   int limit = high;
 
   DCHECK(low <= high);
 
   while (low != high) {
-    int mid = (low + high) / 2;
+    int mid = low + (high - low) / 2;
     Name* mid_name = array->GetSortedKey(mid);
     uint32_t mid_hash = mid_name->Hash();
 
     if (mid_hash >= hash) {
       high = mid;
     } else {
       low = mid + 1;
     }
   }
 
@@ skipping 5088 matching lines @@
 #undef READ_INT64_FIELD
 #undef WRITE_INT64_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_