Singletons/T342.hs:(0,0)-(0,0): Splicing declarations
    do synName <- newName "MyId"
       a <- newName "a"
       let syn = TySynD synName [PlainTV a] (VarT a)
       defuns <- withLocalDeclarations [syn] $ genDefunSymbols [synName]
       pure $ syn : defuns
  ======>
    type MyId a = a
    type MyIdSym1 a0123456789876543210 = MyId a0123456789876543210
    instance SuppressUnusedWarnings MyIdSym0 where
      suppressUnusedWarnings = snd (((,) MyIdSym0KindInference) ())
    data MyIdSym0 a0123456789876543210
      where
        MyIdSym0KindInference :: forall a0123456789876543210
                                        arg. SameKind (Apply MyIdSym0 arg) (MyIdSym1 arg) =>
                                 MyIdSym0 a0123456789876543210
    type instance Apply MyIdSym0 a0123456789876543210 = MyId a0123456789876543210