Returns the list of API levels in this SDK.

Values are returned as a struct with the following fields: struct( abi_revision = "0xED74D73009C2B4E3", api_level = "10", as_u32 = 10, status = "unsupported" )

as_u32 is interesting in the case of special API levels like HEAD. clang only wants to be passed API levels in their numeric form.

The status is not an API to be relied on but the STATUS_* constants can be used.