Add failing test case for UWF_UNWRITTEN_FIELD false negative

[granthenke]

Adds a test case to show a false negative for UWF_UNWRITTEN_FIELD
when assert is used or when Slf4j’s LoggerFactory.getLogger(Foo.class)
is used.

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[granthenke]

This isn't intended to be committed, but just to illustrate the issue.

[granthenke]

Digging in a little, adding assert prevents unwrittenField from being added to declaredFields here because xFactory.isReflectiveClass(classDescriptor) is true.

The same thing happens when LoggerFactory.getLogger(UnreportedUnwrittenField.class); is used.

[granthenke]

It looks like it is marked as a reflective class here because of an LDC (18) op code in the case of assert and LoggerFactory.getLogger(UnreportedUnwrittenField.class);.

FWIW the test passes after removing the !xFactory.isReflectiveClass(classDescriptor) check here.

[granthenke]

In case it's helpful this behavior was introduced in this commit: 9ae2687#diff-bfcd2c82604fc6cb72facf4b143d8394

[wreulicke]

@granthenke Thank you for your PR.
I seem that CI is failing by formatting problem.
Could you apply ./gradlew spotlessApply in your terminal for code format and commit the changes.