Add ability to get last method

This should be useful for testing in case of multiple methods with the
same name.

Signed-off-by: Christoph Höger <christoph.hoeger@tu-berlin.de>
Add a (failing) test for slightly complex constructors

The problem seems to be the "cleaning" of the stack before a
putfield instruction. Obviously the interpreter is either ignoring
branches or gets the stack layout wrong.

Signed-off-by: Christoph Höger <christoph.hoeger@tu-berlin.de>