rascal-core: none of the type-checker tests are run anymore

[jurgenvinju]

Describe the bug

• Comment out the part that executes the GenerateSources module and generates compile(d) tests.
• Then run mvn test:

Tests run: 0, Failures: 0, Errors: 0, Skipped: 0

There should be the type-checker tests left to run... What happens is that a lot of code is executed with lots of debug prints, but none of the tests are actually executed?

Imported: ["MMM"]
Skipping (type-incorrect) def: <|test-modules:///TestModule.rsc|(70,66,<5,0>,<9,1>),"c","c",variableId(),|test-modules:///TestModule.rsc|(97,1,<6,13>,<6,14>),defTypeCall([|test-modules:///TestModule.rsc|(88,8,<6,4>,<6,12>)],function(|file:///Users/jurgenv/git/rascal-core/src/org/rascalmpl/core/library/lang/rascalcore/check/ComputeType.rsc|(1491,65,<50,6>,<50,71>)))>

It's unclear to me what is going on yet, but I think we have to solve this before considering the release of the type-checker. @PaulKlint could you have a look at this? I have my hands full with releasing rascal and the LSP and the maven-plugin.