chore(builtin/cast): cleanup
chore(builtin/cast): cleanup

Signed-off-by: Leonardo de Moura <7610bae85f2b530654cc716772f1fe653373e892@microsoft.com>

levnach/lean,Kha/lean,avigad/lean,htzh/lean,javra/lean,leanprover-community/lean,eigengrau/lean,UlrikBuchholtz/lean,fpvandoorn/lean,leodemoura/lean,leodemoura/lean,eigengrau/lean,rlewis1988/lean,soonhokong/travis_test,avigad/lean,levnach/lean,codyroux/lean0.1,codyroux/lean0.1,johoelzl/lean,soonhokong/lean-windows,johoelzl/lean,c-cube/lean,soonhokong/lean-osx,leanprover/lean,UlrikBuchholtz/lean,levnach/lean,sp3ctum/lean,dselsam/lean,soonhokong/lean-windows,avigad/lean,Kha/lean,fpvandoorn/lean,leanprover/lean,leodemoura/lean,dselsam/lean,fgdorais/lean,UlrikBuchholtz/lean,soonhokong/lean,rlewis1988/lean,soonhokong/lean-windows,dselsam/lean,fgdorais/lean,johoelzl/lean,soonhokong/lean-osx,digama0/lean,soonhokong/lean,leanprover-community/lean,Kha/lean,avigad/lean,fpvandoorn/lean2,levnach/lean,sp3ctum/lean,avigad/lean,fpvandoorn/lean,sp3ctum/lean,fpvandoorn/lean2,levnach/lean,leanprover-community/lean,johoelzl/lean,leanprover-community/lean,c-cube/lean,digama0/lean,javra/lean,fgdorais/lean,eigengrau/lean,digama0/lean,javra/lean,Kha/lean,fpvandoorn/lean,johoelzl/lean,soonhokong/lean,fpvandoorn/lean2,htzh/lean,fgdorais/lean,fgdorais/lean,Kha/lean,c-cube/lean,leanprover-community/lean,dselsam/lean,digama0/lean,soonhokong/travis_test,digama0/lean,leanprover/lean,UlrikBuchholtz/lean,soonhokong/travis_test,sp3ctum/lean,htzh/lean,codyroux/lean0.1,htzh/lean,rlewis1988/lean,leanprover-community/lean,javra/lean,johoelzl/lean,soonhokong/lean-osx,eigengrau/lean,soonhokong/lean-osx,leanprover/lean,rlewis1988/lean,soonhokong/travis_test,fpvandoorn/lean2,eigengrau/lean,soonhokong/lean-windows,javra/lean,leodemoura/lean,fpvandoorn/lean,sp3ctum/lean,digama0/lean,UlrikBuchholtz/lean,avigad/lean,htzh/lean,fgdorais/lean,fpvandoorn/lean,codyroux/lean0.1,leodemoura/lean,dselsam/lean,fpvandoorn/lean2,c-cube/lean,Kha/lean,c-cube/lean,leanprover/lean,rlewis1988/lean,soonhokong/lean-osx,dselsam/lean,soonhokong/lean-windows,rlewis1988/lean,soonhokong/lean,leodemoura/lean,leanprover/lean,soonhokong/lean