Ruby

• import a github pull request
  https://github.com/ruby/ruby/pull/1050
  by Kazuho Oku [email protected].
  This pull request has the following commits.
• gc.c: reduce # of args to 6 (max. of register args on x86-64) so
  that the newobj_of_slowpass can be called via TCO.
• gc.c (newobj_of), string.c (str_duplicate): for performance,
  the hot functions must be inlined.
• gc.c: for performance, preceding arguments of .*newobj_of.*
  must be same, so that the arg registers can be reused in case of
  TCO.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52099 b2dd03c8-39d4-4d8f-98ff-823fe69b080e