mruby-os-memsize
And, in the calculation of the instance variable size, the fraction was always rounded down because of division of integers, so fix it. At the same time, test items that are no longer passed due to this change are deleted.
memsize_of
memsize_of_all
Those methods are originally CRuby specific. Co-authored-by: Yukihiro "Matz" Matsumoto <matz@ruby.or.jp>