feat(library/init/meta/interactive): cases tactic takes arbitrary expressions
feat(library/init/meta/interactive): cases tactic takes arbitrary expressions

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