fix(library/vm/vm_expr): do not use expr_var as both function and class name
fix(library/vm/vm_expr): do not use expr_var as both function and class name

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