feat(library/kernel_bindings): expose instantiate_levels
feat(library/kernel_bindings): expose instantiate_levels

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

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