[modules] Give Module an internal [hash] field

src/isolate.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_ISOLATE_H_
 #define V8_ISOLATE_H_
 
 #include <memory>
 #include <queue>
 
@@ skipping 1051 matching lines @@
 
   FunctionEntryHook function_entry_hook() { return function_entry_hook_; }
   void set_function_entry_hook(FunctionEntryHook function_entry_hook) {
     function_entry_hook_ = function_entry_hook;
   }
 
   void* stress_deopt_count_address() { return &stress_deopt_count_; }
 
   base::RandomNumberGenerator* random_number_generator();
 
+  // Generates a random number that is non-zero when masked
+  // with the provided mask.
+  int GenerateIdentityHash(uint32_t mask);
+
   // Given an address occupied by a live code object, return that object.
   Object* FindCodeObject(Address a);
 
   int NextOptimizationId() {
     int id = next_optimization_id_++;
     if (!Smi::IsValid(next_optimization_id_)) {
       next_optimization_id_ = 0;
     }
     return id;
   }
@@ skipping 596 matching lines @@
 
   EmbeddedVector<char, 128> filename_;
   FILE* file_;
   int scope_depth_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ISOLATE_H_