should not copy promoted flags.

	* include/ruby/ruby.h (rb_clone_setup): should not copy some flags
	  (FL_PROMOTED0|FL_PROMOTED1|FL_FINALIZE).
	  [Bug #13775]

	* test/ruby/test_object.rb: add a test (note that this test will fail
	  only when RGENGC_CHECK_MODE >= 2).


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@59520 b2dd03c8-39d4-4d8f-98ff-823fe69b080e