mruby/mruby — pull request #1874 by ksss (2014-03-16 14:44:06+00:00)
Title: float + nil should be raise TypeError

before
```ruby
1.0+nil #=> 1.0
1.0-nil #=> non float value (TypeError)
```

after
```ruby
1.0+nil #=> non float value (TypeError)
1.0-nil #=> non float value (TypeError)
```