chore(library/kernel_serializer): add assertions for invalid uses of anonymous names
chore(library/kernel_serializer): add assertions for invalid uses of anonymous names

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

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