[llvm] [ADT] Update hash function of uint64_t for DenseMap (PR #95734)

[Chuanqi Xu via llvm-commits]

================
@@ -151,7 +151,7 @@ template<> struct DenseMapInfo<unsigned long long> {
   static inline unsigned long long getTombstoneKey() { return ~0ULL - 1ULL; }
 
   static unsigned getHashValue(const unsigned long long& Val) {
-    return (unsigned)(Val * 37ULL);
+    return DenseMapInfo<unsigned>(Val) ^ DenseMapInfo<unsigned>(Val >> 32);
----------------
ChuanqiXu9 wrote:

That looks good too. But I am not a hashing expert so I don't have an opinion here. Let's see what others propose.

https://github.com/llvm/llvm-project/pull/95734