Fixity resolution not performed inside tuple sections

[ndmitchell]

The code for leafFix misses a case for TupleSection, see

haskell-src-exts/src/Language/Haskell/Exts/Fixity.hs

Lines 382 to 426 in eee7427

	leafFix :: Monad m => [Fixity] -> Exp SrcSpanInfo -> m (Exp SrcSpanInfo)
	leafFix fixs e' = case e' of
	InfixApp l e1 op e2 -> liftM2 (flip (InfixApp l) op) (leafFix fixs e1) (fix e2)
	App l e1 e2 -> liftM2 (App l) (fix e1) (fix e2)
	NegApp l e -> liftM (NegApp l) $ fix e
	Lambda l pats e -> liftM2 (Lambda l) (mapM fix pats) $ fix e
	Let l bs e ->
	let extraFix x = applyFixities (fixs ++ getBindFixities bs) x
	in liftM2 (Let l) (extraFix bs) $ extraFix e
	If l e a b -> liftM3 (If l) (fix e) (fix a) (fix b)
	MultiIf l alts -> liftM (MultiIf l) (mapM fix alts)
	Case l e alts -> liftM2 (Case l) (fix e) $ mapM fix alts
	Do l stmts -> liftM (Do l) $ mapM fix stmts
	MDo l stmts -> liftM (MDo l) $ mapM fix stmts
	Tuple l bx exps -> liftM (Tuple l bx) $ mapM fix exps
	List l exps -> liftM (List l) $ mapM fix exps
	Paren l e -> liftM (Paren l) $ fix e
	LeftSection l e op -> liftM (flip (LeftSection l) op) (fix e)
	RightSection l op e -> liftM (RightSection l op) $ fix e
	RecConstr l n fups -> liftM (RecConstr l n) $ mapM fix fups
	RecUpdate l e fups -> liftM2 (RecUpdate l) (fix e) $ mapM fix fups
	EnumFrom l e -> liftM (EnumFrom l) $ fix e
	EnumFromTo l e1 e2 -> liftM2 (EnumFromTo l) (fix e1) (fix e2)
	EnumFromThen l e1 e2 -> liftM2 (EnumFromThen l) (fix e1) (fix e2)
	EnumFromThenTo l e1 e2 e3 -> liftM3 (EnumFromThenTo l) (fix e1) (fix e2) (fix e3)
	ListComp l e quals -> liftM2 (ListComp l) (fix e) $ mapM fix quals
	ParComp l e qualss -> liftM2 (ParComp l) (fix e) $ mapM (mapM fix) qualss
	ExpTypeSig l e t -> liftM (flip (ExpTypeSig l) t) (fix e)
	BracketExp l b -> liftM (BracketExp l) $ fix b
	SpliceExp l s -> liftM (SpliceExp l) $ fix s
	XTag l n ats mexp cs -> liftM3 (XTag l n) (mapM fix ats) (mapM fix mexp) (mapM fix cs)
	XETag l n ats mexp -> liftM2 (XETag l n) (mapM fix ats) (mapM fix mexp)
	XExpTag l e -> liftM (XExpTag l) $ fix e
	XChildTag l cs -> liftM (XChildTag l) $ mapM fix cs
	Proc l p e -> liftM2 (Proc l) (fix p) (fix e)
	LeftArrApp l e1 e2 -> liftM2 (LeftArrApp l) (fix e1) (fix e2)
	RightArrApp l e1 e2 -> liftM2 (RightArrApp l) (fix e1) (fix e2)
	LeftArrHighApp l e1 e2 -> liftM2 (LeftArrHighApp l) (fix e1) (fix e2)
	RightArrHighApp l e1 e2 -> liftM2 (RightArrHighApp l) (fix e1) (fix e2)
	CorePragma l s e -> liftM (CorePragma l s) (fix e)
	SCCPragma l s e -> liftM (SCCPragma l s) (fix e)
	GenPragma l s ab cd e -> liftM (GenPragma l s ab cd) (fix e)
	LCase l alts -> liftM (LCase l) $ mapM fix alts
	_ -> return e'

. As a result, fixity resolution is not performed inside tuple sections, which causes upstream issues such as ndmitchell/hlint#673 found by @cocreature