SquirrelJME/SquirrelJME

# 2021/06/16

## 18:04

So it looks like the code generation issue of many months ago is due to
`DUP_X1` and `doStackShuffle()` not being the best.

```
DB: Preprocessing STACKSHUFFLE:[DUP_X1] (@62#DUP_X1~:[])
DB: Shuffle with: DUP_X1 -> [[ba] -> [aba]]
DB: Popped: [r13:Ljava/util/LinkedList;, r14:I]
DB: Source map: {1=r13:Ljava/util/LinkedList;, 0=r14:I}
DB: Pre 18 -> 13
DB: Pre-copies: {14=18}
DB: *** Stack Result ***
DB: BEF: State:{L=[r8:Ljava/util/__LinkedListListIterator__;:RN, r9:Ljava/lang/Object;:RN, r10:I, r11:Ljava/util/__Link__;], S=[r8(12):Ljava/util/__LinkedListListIterator__;:N, r13:Ljava/util/LinkedList;, r14:I]}
DB: AFT: State:{L=[r8:Ljava/util/__LinkedListListIterator__;:RN, r9:Ljava/lang/Object;:RN, r10:I, r11:Ljava/util/__Link__;], S=[r8(12):Ljava/util/__LinkedListListIterator__;:N, r13:I, r13(14):Ljava/util/LinkedList;:N, r13(15):I]}
DB: IN : []
DB: OUT: []
DB: OPS: [COPY(14, 18), COPY(18, 13)]
```

As we can see here, the ordering is not correct and the values get trashed.
So if this gets fixed then this issue should go away. Has been awhile since
I looked at the code last but it should hopefully not be too difficult.