Generate stack map frames (Java 6 bytecode feature).
Stack map frames were added in bytecode version 50 (Java 6), and bytecode with version 51 or higher (Java 7+) must have stack map frames.
ExtendJ currently (8.0.1-215-g85fe215) still outputs bytecode version 49 (Java 5).
Some Java 8 features only work if the bytecode has version 52. This includes default interface methods and calling static interface methods. To support these features, ExtendJ must generate stack map frames.