(Init_BareVM): per-VM object space support, which is disabled now.
* gc.c (rb_objspace_alloc), vm.c (Init_BareVM): should not use ruby
malloc here.
* gc.c (garbage_collect, etc): performance improvement by passing the
reference instead of refering the global variable in each functions.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@16218 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
