mruby/mruby — pull request #2486 by IceDragon200 (2014-07-22 16:54:35+00:00)
Title: Proper error handling for instance_eval and friends

Any of the following method calls will result in a segfault when no parameters or block is given:
```ruby
instance_eval
module_eval
class_eval
```

I've patched the methods in question by adding a simple nil check and raising an error if true.