Backport @10366 to 3.6

src/utils.h

Index: src/utils.h
===================================================================
--- src/utils.h	(revision 10379)
+++ src/utils.h	(working copy)
@@ -237,10 +237,13 @@
 // ----------------------------------------------------------------------------
 // Hash function.
 
+static const uint32_t kZeroHashSeed = 0;
+
 // Thomas Wang, Integer Hash Functions.
 // http://www.concentric.net/~Ttwang/tech/inthash.htm
-static inline uint32_t ComputeIntegerHash(uint32_t key) {
+static inline uint32_t ComputeIntegerHash(uint32_t key, uint32_t seed) {
   uint32_t hash = key;
+  hash = hash ^ seed;
   hash = ~hash + (hash << 15);  // hash = (hash << 15) - hash - 1;
   hash = hash ^ (hash >> 12);
   hash = hash + (hash << 2);
@@ -253,7 +256,8 @@
 
 static inline uint32_t ComputePointerHash(void* ptr) {
   return ComputeIntegerHash(
-      static_cast<uint32_t>(reinterpret_cast<intptr_t>(ptr)));
+      static_cast<uint32_t>(reinterpret_cast<intptr_t>(ptr)),
+      v8::internal::kZeroHashSeed);
 }