Type guards doesn't work on multilevel if statements

[tinganho]

I just noticed that type guards doesn't work on multilievel if statements? Is it by design?

var t: string | boolean | number;
if (typeof t === 'boolean' || typeof t === 'number') {
    if (typeof t === 'number') {        
    }
    else {
        t // should be boolean, but is string | boolean
    }
}

[DanielRosenwasser]

I wonder if this is at all related to #4874, but it definitely seems like a bug.

[tinganho]

@DanielRosenwasser I think it is related.

[weswigham]

Fixed by #5442.