Note [Reboxed crud for bottoming calls]

For functions like `get` in Note [Boxity for bottoming functions], it's clear
that the reboxed crud will be floated inside to the call site of `$windexError`.
But here's an example where that is not the case:
```hs
import GHC.Ix

theresCrud :: Int -> Int -> Int
theresCrud x y = go x
  where
    go 0 = index (0,y) 0
    go 1 = index (x,y) 1
    go n = go (n-1)
    {-# NOINLINE theresCrud #