internal.h: allocator function in rb_classext_t
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36925 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
internal.h: allocator function in rb_classext_t
rb_classext_t from ordinary method table. [ruby-dev:46121]
[Feature #6993]
(rb_get_alloc_func): use allocator function in rb_classext_t.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36925 b2dd03c8-39d4-4d8f-98ff-823fe69b080e