tests(util/rb_tree): wrap tst6 with #if !defined
tests(util/rb_tree): wrap tst6 with #if !defined

leanprover-community/lean,digama0/lean,fpvandoorn/lean,c-cube/lean,sp3ctum/lean,johoelzl/lean,soonhokong/travis_test,Kha/lean,dselsam/lean,dselsam/lean,UlrikBuchholtz/lean,soonhokong/lean,eigengrau/lean,c-cube/lean,leanprover-community/lean,soonhokong/lean-osx,htzh/lean,fpvandoorn/lean2,Kha/lean,eigengrau/lean,javra/lean,johoelzl/lean,Kha/lean,rlewis1988/lean,htzh/lean,leanprover-community/lean,eigengrau/lean,fpvandoorn/lean2,rlewis1988/lean,johoelzl/lean,dselsam/lean,leodemoura/lean,dselsam/lean,fpvandoorn/lean,sp3ctum/lean,leanprover/lean,leanprover/lean,htzh/lean,leodemoura/lean,javra/lean,leodemoura/lean,avigad/lean,avigad/lean,fpvandoorn/lean,soonhokong/lean-osx,fgdorais/lean,digama0/lean,sp3ctum/lean,avigad/lean,Kha/lean,UlrikBuchholtz/lean,soonhokong/lean-windows,dselsam/lean,sp3ctum/lean,leodemoura/lean,avigad/lean,sp3ctum/lean,rlewis1988/lean,rlewis1988/lean,avigad/lean,soonhokong/lean,levnach/lean,UlrikBuchholtz/lean,fpvandoorn/lean2,UlrikBuchholtz/lean,digama0/lean,digama0/lean,javra/lean,soonhokong/lean-osx,levnach/lean,digama0/lean,soonhokong/travis_test,fgdorais/lean,fpvandoorn/lean,c-cube/lean,leanprover/lean,dselsam/lean,rlewis1988/lean,johoelzl/lean,levnach/lean,leanprover-community/lean,levnach/lean,leanprover-community/lean,johoelzl/lean,fpvandoorn/lean,Kha/lean,soonhokong/lean-windows,soonhokong/lean-windows,fgdorais/lean,leanprover-community/lean,leanprover/lean,eigengrau/lean,soonhokong/lean,fpvandoorn/lean,javra/lean,digama0/lean,javra/lean,c-cube/lean,johoelzl/lean,soonhokong/lean-windows,leodemoura/lean,soonhokong/lean-osx,fpvandoorn/lean2,htzh/lean,fgdorais/lean,fgdorais/lean,leanprover/lean,UlrikBuchholtz/lean,fpvandoorn/lean2,soonhokong/lean-osx,fgdorais/lean,soonhokong/lean,avigad/lean,eigengrau/lean,c-cube/lean,rlewis1988/lean,levnach/lean,soonhokong/travis_test,leodemoura/lean,soonhokong/lean,leanprover/lean,htzh/lean,Kha/lean,soonhokong/lean-windows,soonhokong/travis_test