Make fixer for CS0535 smarter when implementing IEnumerable<T>

[DoctorKrolic]

Given code like:

class MyClass : IEnumerable<int>
{
    
}

Th fixer for CS0535 currently doesn't treat this case as some kind of special, so applying it just creates method declarations for non-implemented members:

using System.Collections;

class MyClass : IEnumerable<int>
{
    public IEnumerator<int> GetEnumerator()
    {
        throw new NotImplementedException();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        throw new NotImplementedException();
    }
}

However, implementation for non-generic enumerator in 99.99% cases would be then changed by user to

IEnumerator IEnumerable.GetEnumerator()
{
    return GetEnumerator();
}

I think, considering that, fixer for CS0535 can be made smarter in this specific case and produce code like this in the first place:

using System.Collections;

class MyClass : IEnumerable<int>
{
    public IEnumerator<int> GetEnumerator()
    {
        throw new NotImplementedException();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }
}

[mavasani]

Assigning to @CyrusNajmabadi to review/triage the feature request.

[CyrusNajmabadi]

Yes. This would be nice to do.

[CyrusNajmabadi]

We woudl take a targeted user pr here.