ut_fold_ull() and ut_hash_ulint() are a waste

On 64-bit CPU architectures, the default InnoDB data type ulint, which is an alias of size_t is 64 bits wide.

The function ut_fold_ull() is converting a 64-bit integer to ulint. It can be simplified on 32-bit systems, and we could avoid the extra instructions altogether on 64-bit systems and just use the 64-bit index or table identifiers as is.

The function ut_hash_ulint() seems to be an unnecessary obfuscation. Computing an exclusive OR with a constant before performing a modulus operation does not seem to affect the entropy at all.