Integrate Jasmin to generate the test classes

Some of the verifier test cases rely on hand crafted .class files. These class file are sourceless because they contain intentional errors and can't be generated from a Java source file. However it should be possible to generate them from Jasmin files.

Jasmin is available from the conjars repository, embedded in the soot:soot artifact. It could be integrated in the Maven build using the maven-antrun-plugin attached to the generate-test-resources phase.