util/hash_table: Fix hashing in clears on 32-bit

util/hash_table: Fix hashing in clears on 32-bit

Some hash functions (eg. key_u64_hash) will attempt to dereference the
key, causing an invalid access when passed DELETED_KEY_VALUE (0x1) or
FREED_KEY_VALUE (0x0).

When in 32-bit arch a 64-bit key value doesn't fit into a pointer, so
hash_table_u64 internally use a pointer to a struct containing the
64-bit key value.

Fix _mesa_hash_table_u64_clear() to handle the 32-bit case by creating a
temporary hash_key_u64 to pass to the hash function.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Suggested-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Cc: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Cc: Nicolai Hähnle <nicolai.haehnle@amd.com>