Do not store duplicates of inherited static fields in tests for --static-values

[antlechner]

In the tests for the --static-values option, we previously stored the value for an inherited static field twice, when it fact it is only needed in its declaring class.

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[majakusber]

I didn't quite understand the structure of these tests, only after some offline discussion. Consider adding a note to the readme file about the script in the cprover folder being just a simplified version of the actual, internal script.

[majakusber]

❓ Is this how it works in the actual script too?

[antlechner]

It will be. 🙂
The "actual script" comments might be confusing for some people. I'll think about how to resolve this and will try to add some more info in a follow-up PR.

[allredj]

✔️
Passed Diffblue compatibility checks (cbmc commit: 057e4da).
Build URL: https://travis-ci.com/diffblue/test-gen/builds/117691838