cleanup(Client): guard emitting GMU and PU on user updates (#5655)

src/structures/GuildMember.js

@@ -346,6 +346,29 @@ class GuildMember extends Base {
     return this.guild.members.fetch({ user: this.id, cache: true, force });
   }
 
+  /**
+   * Whether this guild member equals another guild member. It compares all properties, so for most
+   * comparison it is advisable to just compare `member.id === member2.id` as it is significantly faster
+   * and is often what most users need.
+   * @param {GuildMember} member The member to compare with
+   * @returns {boolean}
+   */
+  equals(member) {
+    return (
+      member instanceof this.constructor &&
+      this.id === member.id &&
+      this.partial === member.partial &&
+      this.guild.id === member.guild.id &&
+      this.joinedTimestamp === member.joinedTimestamp &&
+      this.lastMessageID === member.lastMessageID &&
+      this.lastMessageChannelID === member.lastMessageChannelID &&
+      this.nickname === member.nickname &&
+      this.pending === member.pending &&
+      (this._roles === member._roles ||
+        (this._roles.length === member._roles.length && this._roles.every((role, i) => role === member._roles[i])))
+    );
+  }
+
   /**
    * When concatenated with a string, this automatically returns the user's mention instead of the GuildMember object.
    * @returns {string}