Crash in instance_eval and instance_exec

[clayton-shopify]

The following input demonstrates a crash:

instance_eval { super &0 }

This issue was reported by https://hackerone.com/d4nny

I noticed that the following also crashes:

instance_exec { super &0 }

And the following don't behave as expected. In MRI they result in "super called outside of method" but in MRuby the results are different:

$ bin/mirb
mirb - Embeddable Interactive Ruby Shell

> instance_eval { super 0 }
(mirb):1: expected String (TypeError)
> instance_exec { super 0 }
(mirb):2: no block given (ArgumentError)

[matz]

Will be fixed. instance_eval can take a string argument where instance_exec cannot. That's the reason they raise different exceptions.