Accept unboxed tuples in type signatures
ubx_tup | not gla_exts = UT_NotOk
| otherwise = case ctxt of
TySynCtxt _ -> UT_Ok
ubx_tup | not gla_exts = UT_NotOk
| otherwise = case ctxt of
TySynCtxt _ -> UT_Ok
other -> UT_NotOk
-- Unboxed tuples ok in function results,
-- but for type synonyms we allow them even at
other -> UT_NotOk
-- Unboxed tuples ok in function results,
-- but for type synonyms we allow them even at