Adding type annotation to curried function emits compiler error

[mediremi]

Since v12.0.0-alpha.6, adding a type annotation to a curried function gives the error This function is a curried function where an uncurried function is expected:

type fn2 = (int, int) => int
let add : fn2 = (a, b) => a + b
let add5 : int => int  =  add(5, ...)
/// This function is a curried function where an uncurried function is expected

(Playground link)

[cristianoc]

Good catch. #7548