* vm.c (ruby_vm_destruct): do not use ruby_xfree() after freeing
  objspace.
* gc.c (ruby_mimfree): added. It is similar to ruby_mimmalloc().
* internal.h: ditto.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43771 b2dd03c8-39d4-4d8f-98ff-823fe69b080e