Fixed sql_discovery.simple failure.
storage/sequence/sequence.cc:
Let sequence share class have unique name to avoid collision with other
classes.
storage/test_sql_discovery/test_sql_discovery.cc:
Let test_sql_discovery share class have unique name to avoid collision with
other classes.
Fixed test_sql_discovery compilation failure.
storage/test_sql_discovery/mysql-test/archive/discover.rdiff:
archive.discover result has changed during merge. Adjusted discover.rdiff
accordingly.
storage/test_sql_discovery/test_sql_discovery.cc:
Adjusted test_sql_discovery according to:
WL#4305 - storage-engine private data area per physical table.