func (b *Builder) addVariable(u types.Universe, useName *types.Name, in *tc.Var) *types.Type {
name := tcVarNameToName(in.String())
if useName != nil {
name = *useName
}
out := u.Variable(name)
out.Kind = types.DeclarationOf
out.Underlying = b.walkType(u, nil, in.Type())
return out
}