[modules] Give Module an internal [hash] field

src/isolate.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/isolate.h"
 
 #include <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
@@ skipping 2865 matching lines @@
     if (FLAG_random_seed != 0) {
       random_number_generator_ =
           new base::RandomNumberGenerator(FLAG_random_seed);
     } else {
       random_number_generator_ = new base::RandomNumberGenerator();
     }
   }
   return random_number_generator_;
 }
 
+int Isolate::GenerateIdentityHash(uint32_t mask) {
+  int hash;
+  int attempts = 0;
+  do {
+    hash = random_number_generator()->NextInt() & mask;
+  } while (hash == 0 && attempts++ < 30);
+  return hash != 0 ? hash : 1;
+}
 
 Object* Isolate::FindCodeObject(Address a) {
   return inner_pointer_to_code_cache()->GcSafeFindCodeForInnerPointer(a);
 }
 
 
 #ifdef DEBUG
 #define ISOLATE_FIELD_OFFSET(type, name, ignored)                       \
 const intptr_t Isolate::name##_debug_offset_ = OFFSET_OF(Isolate, name##_);
 ISOLATE_INIT_LIST(ISOLATE_FIELD_OFFSET)
@@ skipping 419 matching lines @@
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8