Missing Note about linear types, maybe redundant code too
In GHC.Core.Opt.Simplify.Iteration I see this comment
```
Since this transformation is tantamount to a binder swap, the same caveat as in
Note [Suppressing binder-swaps on linear case] in OccurAnal apply.
```
It annotates this code in that same module:
```
-- See Note [Add unfolding for scrutinee]
env2 | Many <- idMult case_bndr = case scrut of
Just (Var v) -> addBinderUnfolding env1 v con_app_unf
```
However
* There is no `Note [Suppressing binder-swaps on linear case]`
* I can see nothing analogous in OccurAnal
This comment was introduced in the mega-patch when linear types landed
```
commit 40fa237e1daab7a76b9871bb6c50b953a1addf23
Author: Krzysztof Gogolewski <krzysztof.gogolewski@tweag.io>
Date: Mon Jun 15 19:58:10 2020 +0200
Linear types (#15981)
```
This was before we had linting to detect bad Note references.
Questions
1. Can we get rid of the `Many <- idMult case_bndr` guard above?
2. Or do we instead need to add something in OccurAnal?
issue