[MCOMPILER-540] - useIncrementalCompilation=false may add generated sources to the sources list

[mensinda]

See MCOMPILER-540.

This PR fixes the bug by filtering out the generated sources from the stale sources list.

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[elharo]

This could use a test that exposes the bug.

[yanye666]

This could use a test that exposes the bug.

why not merge

[mensinda]

As requested, I have added a test case.

NOTE: The added test case will only pass once #191 is merged, or MCOMPILER-538 is fixed another way.