bignum.c: Bignum zero comparison

* bignum.c (rb_big_eq): test as Fixnum if possible and get rid of zero
  length Bignum.  [ruby-core:53893] [Bug #8204]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40076 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
bignum.c: hide intermediate Bignums

* bignum.c (rb_big_eq): hide intermediate Bignums not just freeing
  memory.  [ruby-core:53893] [Bug #8204]
* object.c (rb_obj_hide): hide an object by clearing klass.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40077 b2dd03c8-39d4-4d8f-98ff-823fe69b080e