* gc.c (RGENGC_CHECK_MODE): add new check mode `3'.
  In this mode, show all references if there is
  a miss-corrected object.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41401 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* gc.c (rgengc_remember): check T_NONE and T_ZOMBIE
  if RGENGC_CHECK_MODE > 0.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41402 b2dd03c8-39d4-4d8f-98ff-823fe69b080e