Hey folks! I'm moving my library crates to `portable-atomic` and I have a doubt regarding the features to be enabled. Right now I specify the dependency as:
```
portable-atomic = { version = "1.4", default-features = false, features = ["require-cas"] }
```
And leave two features to let users use either `critical-section` or `unsafe-assume-single-core`:
```
critical-section = ["portable-atomic/critical-section"]
unsafe-assume-single-core = ["portable-atomic/unsafe-assume-single-core"]
```
Am I right or is this overly complicated?