[Bug-Candidate]: Slither cannot recognize the selector of locally declared functions.

### Describe the issue:

In Yul, Slither cannot recognize the selector of locally declared functions.

### Code example to reproduce the issue:

```
contract C {
function f() public {
function() external g;
assembly {
g.selector := 1
}
}
}
```

### Version:

0.11.3

### Relevant log output:

```shell
ERROR:root:Error:
ERROR:root:unresolved reference to identifier g.selector
ERROR:root:Please report an issue to https://github.com/crytic/slither/issues
```