message: Checksum should not use hash function
diff: namespace duckdb {
  +hash_t Checksum(uint64_t x) {
  + return x * UINT64_C(0xbf58476d1ce4e5b9);
  +}
  +
  uint64_t Checksum(uint8_t *buffer, size_t size) {
  uint64_t result = 5381;
  uint64_t *ptr = (uint64_t *)buffer;
  size_t i;
  - // for efficiency, we first hash uint64_t values
  + // for efficiency, we first checksum uint64_t values
  for (i = 0; i < size / 8; i++) {
  - result ^= Hash(ptr[i]);
  + result ^= Checksum(ptr[i]);
  }
  if (size - i * 8 > 0) {
  // the remaining 0-7 bytes we hash using a string hash
  