Proposal: add fuzz test to the sootup project

[virusdefender]

In order to better discover bugs like

• IR building fail to halt in some test cases #714
• Aggregator type cast bug #739
• JavaIdentifierFactory's fromPath may crash when handling paths with META-INF #675

I think sootup could add a test based on a large dataset of jar files.

The main process is:

1. Collect various versions of rt.jar and jrt.jmod
2. Collect various versions of commonly seen jar files on maven (top 5000 downloads?)
3. Add corresponding test codes, such as being able to correctly parse each class, generate all the variables in jimple with the correct types, etc.

With these fundamentals, we can do more things in the future, such as

• Add more module tests, like FlowAnalysis
• Code performance and quality optimization

[virusdefender]

I pushed a simple fuzz test project

1. git clone https://github.com/virusdefender/sootup-fuzztest.git
2. add rt.jar to data dir (downloaded from https://cdn.azul.com/zulu/bin/zulu8.74.0.17-ca-jre8.0.392-linux_x64.zip)
3. use maven to installSootUp jar dependencies to local repo
4. run Main

This project can expose many different bugs, due to the number of different exceptions and timeouts involved. I can't submit each issue individually, but if you're interested, you can try running it to see for yourself.