chore(builtin): cleanup cmake file
chore(builtin): cleanup cmake file

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

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