mruby/mruby — pull request #394 by silverhammermba (2012-07-25 22:29:12+00:00)
Title: Undefine class method new rather than instance method.

> [nil, false, true, 0, 0.0].map { |x| x.class.new.class }
=> [NilClass, FalseClass, TrueClass, Fixnum, Float]

Also add mrb_undef_class_method for DRYness.