subject_name: derive traits for GeneralDnsNameRef

This commit derives `Clone`, `Copy`, `Eq`, `PartialEq`, and `Hash` for
`GeneralDnsNameRef`. This type is an enum that contains either
a `DnsNameRef` or a `WildcardDnsNameRef`, and both of these types
already derive this same list of traits. Adding them to
`GeneralDnsNameRef` makes the type easier to work with.

Author: cpu

src/subject_name/dns_name.rs

@@ -143,6 +143,7 @@ impl<'a> From<DnsNameRef<'a>> for &'a str {
 /// A DNS name that may be either a DNS name identifier presented by a server (which may include
 /// wildcards), or a DNS name identifier referenced by a client for matching purposes (wildcards
 /// not permitted).
+#[derive(Clone, Copy, Eq, PartialEq, Hash)]
 pub enum GeneralDnsNameRef<'name> {
     /// a reference to a DNS name that may be used for matching purposes.
     DnsName(DnsNameRef<'name>),