There are 2 different anonymous struct declarations that require
different approaches:

1. var x struct{...}
2. x := struct{...}{}

For the first one we can use the existing solution just with a minor
update. However, it returns the wrong docs for the fields of nested
structs. To fix this we need to visit all fields recursively.

The second one is not a generic declaration. So, the simplest solution
is to use the method Snapshot.PosToField.

Fixes golang/go#43675

There are 2 different anonymous struct declarations that require
different approaches:

1. var x struct{...}
2. x := struct{...}{}

For the first one we can use the existing solution with a minor update.
However, it returns the wrong docs for the fields of nested structs.
To fix this we need to visit all fields recursively.

The second one is not a generic declaration. So, the simplest solution
is to use the method Snapshot.PosToField.

Fixes golang/go#43675

There are 2 different anonymous struct declarations that require
different approaches:

1. var x struct{...}
2. x := struct{...}{}

For the first one we can use the existing solution with a minor update.
However, it returns the wrong docs for the fields of nested structs.
To fix this we need to visit all fields recursively.

The second one is not a generic declaration. So, the simplest solution
is to use the method Snapshot.PosToField.

Fixes golang/go#43675