[modules] Give Module an internal [hash] field

src/heap/heap.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/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/context-slot-cache.h"
 #include "src/base/bits.h"
@@ skipping 3996 matching lines @@
   // Statically ensure that it is safe to allocate symbols in paged spaces.
   STATIC_ASSERT(Symbol::kSize <= kMaxRegularHeapObjectSize);
 
   HeapObject* result = nullptr;
   AllocationResult allocation = AllocateRaw(Symbol::kSize, OLD_SPACE);
   if (!allocation.To(&result)) return allocation;
 
   result->set_map_no_write_barrier(symbol_map());
 
   // Generate a random hash value.
-  int hash;
-  int attempts = 0;
-  do {
-    hash = isolate()->random_number_generator()->NextInt() & Name::kHashBitMask;
-    attempts++;
-  } while (hash == 0 && attempts < 30);
-  if (hash == 0) hash = 1;  // never return 0
+  int hash = isolate()->GenerateIdentityHash(Name::kHashBitMask);
 
   Symbol::cast(result)
       ->set_hash_field(Name::kIsNotArrayIndexMask | (hash << Name::kHashShift));
   Symbol::cast(result)->set_name(undefined_value());
   Symbol::cast(result)->set_flags(0);
 
   DCHECK(!Symbol::cast(result)->is_private());
   return result;
 }
 
@@ skipping 2475 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8