Check if `->` works for uncurried functions.

[cristianoc]

#5585 (comment)

[cristianoc]

Does not seem to work:

let curried = (x, y) => x + y

let uncurried = (. x, y) => x + y

let c = 3->curried(4)

let uc = (3)->uncurried(. 4) // This function expected 2 arguments, but got 1