[clusterfuzz] Length 0 is perfectly fine for BitVector.

src/bit-vector.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_DATAFLOW_H_
 #define V8_DATAFLOW_H_
 
 #include "src/allocation.h"
 #include "src/zone.h"
 
@@ skipping 48 matching lines @@
   };
 
   static const int kDataBits = kPointerSize * 8;
   static const int kDataBitShift = kPointerSize == 8 ? 6 : 5;
   static const uintptr_t kOne = 1;  // This saves some static_casts.
 
   BitVector(int length, Zone* zone)
       : length_(length),
         data_length_(SizeFor(length)),
         data_(zone->NewArray<uintptr_t>(data_length_)) {
-    DCHECK(length > 0);
+    DCHECK_LE(0, length);
     Clear();
   }
 
   BitVector(const BitVector& other, Zone* zone)
       : length_(other.length()),
         data_length_(SizeFor(length_)),
         data_(zone->NewArray<uintptr_t>(data_length_)) {
     CopyFrom(other);
   }
 
-  static int SizeFor(int length) { return 1 + ((length - 1) / kDataBits); }
+  static int SizeFor(int length) {
+    if (length == 0) return 1;
+    return 1 + ((length - 1) / kDataBits);
+  }
 
   void CopyFrom(const BitVector& other) {
     DCHECK(other.length() <= length());
     for (int i = 0; i < other.data_length_; i++) {
       data_[i] = other.data_[i];
     }
     for (int i = other.data_length_; i < data_length_; i++) {
       data_[i] = 0;
     }
   }
@@ skipping 151 matching lines @@
     bits_ = new_bits;
   }
 
   BitVector* bits_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_DATAFLOW_H_