Bug with effect system and forward declarations

[GULPF]

type 
    SafeFn = proc (): void {. raises: [] }

proc ok() {. raises: [] .} = discard
proc fail() {. raises: [] .}

let f1 : SafeFn = ok
let f2 : SafeFn = fail # Error: type mismatch: got (proc ()) but expected 'SafeFn = proc (){.closure.}'
                       # .raise effect is 'can raise any'


proc fail() = discard

If fail is implemented before it's used, it works.