chore(library/compiler/preprocess_rec): add extra assertions
chore(library/compiler/preprocess_rec): add extra assertions

avigad/lean,leanprover-community/lean,leodemoura/lean,rlewis1988/lean,fpvandoorn/lean,dselsam/lean,Kha/lean,soonhokong/lean-osx,leodemoura/lean,digama0/lean,johoelzl/lean,rlewis1988/lean,leanprover-community/lean,digama0/lean,avigad/lean,digama0/lean,fgdorais/lean,dselsam/lean,leanprover-community/lean,johoelzl/lean,soonhokong/lean-osx,johoelzl/lean,leodemoura/lean,leanprover-community/lean,leanprover/lean,soonhokong/lean-windows,Kha/lean,johoelzl/lean,digama0/lean,leanprover/lean,fgdorais/lean,leanprover/lean,leanprover/lean,leodemoura/lean,leanprover/lean,soonhokong/lean-windows,fgdorais/lean,Kha/lean,dselsam/lean,fgdorais/lean,avigad/lean,johoelzl/lean,Kha/lean,leanprover/lean,digama0/lean,fpvandoorn/lean,dselsam/lean,rlewis1988/lean,rlewis1988/lean,rlewis1988/lean,Kha/lean,fpvandoorn/lean,avigad/lean,fpvandoorn/lean,soonhokong/lean-windows,soonhokong/lean-osx,avigad/lean,soonhokong/lean-windows,johoelzl/lean,leodemoura/lean,soonhokong/lean-osx,rlewis1988/lean,leanprover-community/lean,fpvandoorn/lean,fgdorais/lean,avigad/lean,fgdorais/lean,leodemoura/lean,soonhokong/lean-osx,fpvandoorn/lean,Kha/lean,soonhokong/lean-windows,leanprover-community/lean,digama0/lean,dselsam/lean,dselsam/lean