Fix regression in iloc with boolean list
- [x] closes #36741
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

Run tests in ``indexes`` and ``indexing`` locally without failure.
cc @simonjayhawkins @jreback 

Is this early enough to get into 1.1.4? @phofl it appears the test got lost in the merge Thanks very much. That was not that clever :) code fix is ok, but this is going to be tricky to backport as this code as changed a bit.

cc @jbrockmendel merge if looks good to you. this is fine, thanks @phofl 

not sure how hard the actual backport to 1.1.4 is @meeseeksdev backport 1.1.x Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

```
$ git checkout 1.1.x
$ git pull
```

2. Cherry pick the first parent branch of the this PR on top of the older branch:
```
$ git cherry-pick -m1 52925335fe6d5f1ea6c79bb03da70654d9be9668
```

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

```
$ git commit -am 'Backport PR #37432: Fix regression in iloc with boolean list'
```

4. Push to a named branch :

```
git push YOURFORK 1.1.x:auto-backport-of-pr-37432-on-1.1.x
```

5. Create a PR against branch 1.1.x, I would have named this PR:

> "Backport PR #37432 on branch 1.1.x"

And apply the correct labels and milestones.

Congratulation you did some good work ! Hopefully your backport PR will be tested by the continuous integration and merged soon!

If these instruction are inaccurate, feel free to [suggest an improvement](https://github.com/MeeseeksBox/MeeseeksDev).
                 yep this needs manual. @phofl @simonjayhawkins 