Semigroup instance inverted

```haskell
ghci> sconcat (First 'a' :| [First 'b'])
First {getFirst = 'a'}
ghci> sconcat ((Rec.rnil & Rec.rcons (#foo Rec.:= First 'a')) :| [(Rec.rnil & Rec.rcons (#foo Rec.:= First 'b'))])
[("foo","First {getFirst = 'b'}")]
```

I’d expect both to return the same result, since all I did was to wrap the `First` in a `#foo` field …