MySQL: ALTER TABLE RENAME AS

[altmannmarcelo]

Add support for RENAME AS in ALTER TABLE. This is a MySQL extension.

[iffyio]

Could we introduce a wrapper enum to encode this new alternative behavior? thinking something like

enum RenameTableNameKind {
    As(ObjectName),
    To(ObjectName)
}
RenameTable { table_name: RenameTableNameKind }