Type hints break for some tuple cases

Yaay, first F# hints bug!

**Repro steps**

Here is the code leading to crashes.
```fsharp
module Test =
    let test() =
        fun (a, (b, c)) -> (a, b, c)
```

**Expected behavior**

At least no crash, at best the actual hints.

**Actual behavior**

Crash.

**Known workarounds**

Turn off type hints.