:info (->) inconsistent: Requires -> to be parenthesized but not <->
## Summary
`:info` for the function arrow requires parentheses `:info (->)`
```haskell
$ devbug
GHCi, version 8.11.0.20200403: https://www.haskell.org/ghc/ :? for help
Prelude>
Prelude> :i ->
<interactive>:1:1: error: parse error on input `->'
Prelude>
Prelude> :i (->)
type (->) :: * -> * -> *
data (->) a b
-- Defined in `GHC.Prim'
infixr -1 ->
instance Applicative ((->) r) -- Defined in `GHC.Base'
instance Functor ((->) r) -- Defined in `GHC.Base'
instance Monad ((->) r) -- Defined in `GHC.Base'
instance Monoid b => Monoid (a -> b) -- Defined in `GHC.Base'
instance Semigroup b => Semigroup (a -> b) -- Defined in `GHC.Base'
Prelude>
Prelude>
```
For any other "type operator" it doesn't matter
```haskell
Prelude> :set -XTypeOperators
Prelude> data a <-> b = Iso (a->b) (b->a)
Prelude> :i <->
type (<->) :: * -> * -> *
data (<->) a b = Iso (a -> b) (b -> a)
-- Defined at <interactive>:3:1
Prelude> :i (<->)
type (<->) :: * -> * -> *
data (<->) a b = Iso (a -> b) (b -> a)
-- Defined at <interactive>:3:1
```
## Expected behavior
`:info ->` should work just as `:info <->` does.
## Environment
* GHC version used: 8.11.0.20200403
issue