* gc.c (rb_objspace_call_finalizer): finalize_deferred may free up
a object which is reachable from a part after this function,
e.g. ruby_vm_destruct(). [ruby-dev:46647] [Bug #7452]
* test/ruby/test_gc.rb (test_finalizing_main_thread): add a test
for above.
* test/rdoc/test_rdoc_servlet.rb: Tets for above
merge revision(s) 38010: [Backport #7452]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@38831 b2dd03c8-39d4-4d8f-98ff-823fe69b080e