`return` inside a literal can break JVM stack

[fglock]

return inside a literal can break JVM stack.

example workaround in List constructor:

            // emit the list element
            if (element instanceof OperatorNode && ((OperatorNode) element).operator.equals("return")) {
                // Special case for return operator: it inserts a `goto` instruction
                emitterVisitor.ctx.logDebug("visit(ListNode) return");
                emitterVisitor.ctx.mv.visitInsn(Opcodes.POP); // stop construction of RuntimeList instance
                emitterVisitor.ctx.mv.visitInsn(Opcodes.POP);
                element.accept(emitterVisitor.with(RuntimeContextType.LIST));
                return;
            } else {
                element.accept(emitterVisitor.with(RuntimeContextType.LIST));
            }

another possible workaround: use exceptions