cont.c: avoid needless branch for dmark callbacks
gc.c (gc_mark_children, case T_DATA) does not use the dmark function pointer if DATA_PTR is NULL
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57614 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
cont.c: avoid needless branch for dmark callbacks
gc.c (gc_mark_children, case T_DATA) does not use
the dmark function pointer if DATA_PTR is NULL
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57614 b2dd03c8-39d4-4d8f-98ff-823fe69b080e