[Shaman] Various fixes to Doom Winds

- Now procs Windfury and Flametongue Attack
- Now benefits from its own buff for proccing Windfury

engine/class_modules/sc_shaman.cpp

@@ -7301,20 +7301,29 @@ struct stormkeeper_t : public shaman_spell_t
 
 // Doom Winds Spell ===========================================================
 
-struct doom_winds_t : public shaman_spell_t
+struct doom_winds_t : public shaman_attack_t
 {
   doom_winds_t( shaman_t* player, util::string_view options_str ) :
-    shaman_spell_t( "doom_winds", player, player->talent.doom_winds )
+    shaman_attack_t( "doom_winds", player, player->talent.doom_winds )
   {
     parse_options( options_str );
-    may_crit = false;
+
+    weapon = &( player->main_hand_weapon );
+    weapon_multiplier = 0.0;
   }
 
-  void execute() override
+  void init() override
   {
-    shaman_spell_t::execute();
+    shaman_attack_t::init();
 
+    may_proc_stormbringer = false;
+  }
+
+  void execute() override
+  {
     p()->buff.doom_winds->trigger();
+
+    shaman_attack_t::execute();
   }
 };