Hi, I'm Treeston, and welcome to Combat PR Prep Refactors.

Today, we're moving UNIT_FLAG_IMMUNE_TO_PC and UNIT_FLAG_IMMUNE_TO_NPC to higher-level abstraction so combat manager can react to it.
New methods on Unit:
- void SetImmuneTo<All/PC/NPC>(apply, keepCombat = false);
- bool IsImmuneTo<All/PC/NPC>() const;

# Conflicts:
#	src/server/game/AI/ScriptedAI/ScriptedEscortAI.cpp
#	src/server/game/Entities/Unit/Unit.cpp
#	src/server/game/Spells/SpellEffects.cpp
#	src/server/scripts/EasternKingdoms/BlackrockMountain/BlackrockDepths/boss_tomb_of_seven.cpp
#	src/server/scripts/EasternKingdoms/ScarletEnclave/chapter1.cpp
#	src/server/scripts/EasternKingdoms/ScarletEnclave/chapter2.cpp
#	src/server/scripts/EasternKingdoms/ShadowfangKeep/instance_shadowfang_keep.cpp
#	src/server/scripts/EasternKingdoms/ZulAman/zulaman.cpp
#	src/server/scripts/EasternKingdoms/ZulGurub/boss_mandokir.cpp
#	src/server/scripts/EasternKingdoms/zone_tirisfal_glades.cpp
#	src/server/scripts/Kalimdor/CavernsOfTime/CullingOfStratholme/culling_of_stratholme.cpp
#	src/server/scripts/Kalimdor/WailingCaverns/wailing_caverns.cpp
#	src/server/scripts/Kalimdor/zone_dustwallow_marsh.cpp
#	src/server/scripts/Kalimdor/zone_stonetalon_mountains.cpp
#	src/server/scripts/Kalimdor/zone_tanaris.cpp
#	src/server/scripts/Northrend/IcecrownCitadel/icecrown_citadel.cpp
#	src/server/scripts/Northrend/Naxxramas/boss_thaddius.cpp
#	src/server/scripts/Northrend/Nexus/EyeOfEternity/boss_malygos.cpp
#	src/server/scripts/Outland/TempestKeep/arcatraz/boss_harbinger_skyriss.cpp

src/server/game/Entities/GameObject/GameObject.cpp

@@ -2001,7 +2001,7 @@ void GameObject::CastSpell(Unit* target, uint32 spellId, TriggerCastFlags trigge
         return;
 
     // remove immunity flags, to allow spell to target anything
-    trigger->RemoveFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_IMMUNE_TO_NPC | UNIT_FLAG_IMMUNE_TO_PC);
+    trigger->SetImmuneToAll(false);
 
     if (Unit* owner = GetOwner())
     {