* gc.c (gc_mark): get rid of pushing useless objests.
	* gc.c (rgengc_rememberset_mark): bypass gc_mark() in order to push
	  sunny old object at minor gc.
	* gc.c (gc_mark_children): move sunny old check to gc_mark().
	* gc.c (rgengc_check_shady): remove DEMOTE that already unnecessary.
	* gc.c (rb_gc_writebarrier): ditto.
	  
	  change sunny old check point in order to save mark stack and
	  remove unnatural rest_sweep & demote.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41097 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* remove trailing spaces.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41098 b2dd03c8-39d4-4d8f-98ff-823fe69b080e