`scope(exit)` should not be allowed in the main scope of `noreturn` functions

[dlangBugzillaToGithub]

basile-z reported this on 2024-03-29T07:08:11Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=24466

CC List

Description

consider the following code

```d
noreturn v(int a)
{
    scope(exit) a++; // cant be executed    
    {
        scope(exit) a++; // this one is okay
    }
    assert(0);
}
```

There should be a sema error for the first scope guard as the defered expression statement cannot be executed.

[dlangBugzillaToGithub]

elpenguino+D commented on 2024-03-29T07:18:37Z

I don't think it's accurate to do that for all noreturn scopes. Consider:
```
noreturn v(int a) {
    scope(exit) a++;
    {
        scope(exit) a++;
    }
    throw new Exception("Exception");
}
```

In this code, both scope guards should be executed.