Invalid output code when using a generic type alias to a struct union

[Tarmil]

This issue appeared recently, I suspect the fix for #906 to be causing it.

    type Result<'T> = Result<'T,string>

    let get() : Result<int>= Ok 42

    let test() =
        match get() with
            | Ok y -> string y
            | _ -> "Error"

The above returns "Error"; without the Result<int> type annotation, it returns "42".

// Faulty output (with type alias annotation)
 HelloWorld.test=function()
 {
  HelloWorld.get();
  return void 0==0?Global.String(void 0):"Error";
 };

// Correct output (without type alias annotation)
 HelloWorld.test=function()
 {
  var m;
  m=HelloWorld.get();
  return m.$==0?Global.String(m.$0):"Error";
 };

(Thanks @cata for reporting this on gitter and working together on a repro!)

[Tarmil]

Also to note is that this only happens if the aliased type is a struct.

[Tarmil]

Actually this still fails when reverting the #906 fix, so that's not the cause.

[Jand42]

Issue was not all uses of looking at F# types resolved type aliases. For example accessing a struct union is wrapped in an AddressOf case by FCS, and the code ignoring this when it is a local variable was not resolving type aliases.

[cata]

@Tarmil - Thanks for fixing this!