Spoon fails to mark @SuppressWarnings package as implicit if named element is used

I've no idea why this happens, but if you write this:

```java
@SuppressWarnings(value="unchecked")
```
then Spoon will not mark `java.lang` as implicit, and the output will be:

```java
@java.lang.SuppressWarnings(value="unchecked")
```

Took me an hour of debugging to figure out ... To be clear, the problem is the use of a named element, if you remove the `value=`, it the annotation type's package gets properly marked as implicit.

Reproduce the issue with the two @SuppressWarnings examples in the report and compare the generated output. Trace how Spoon handles named annotation elements and implicit annotation-type packages. Done means the named-element form also emits SuppressWarnings without the java.lang qualification, matching the unnamed form.

Written by the indexing model from the issue text.