Core: Use new SpellInfo class in core. Sadly, this commit is not compatibile with some of the custom code. To make your code work again you may need to change:

*SpellEntry is now SpellInfo
*GetSpellProto is now GetSpellInfo
*SpellEntry::Effect*[effIndex] is now avalible under SpellInfo.Effects[effIndex].*
*sSpellStore.LookupEntry is no longer valid, use sSpellMgr->GetSpellInfo()
*SpellFunctions from SpellMgr.h like DoSpellStuff(spellId) are now: spellInfo->DoStuff()
*SpellMgr::CalculateEffectValue and similar functions are now avalible in SpellEffectInfo class.
*GET_SPELL macro is removed, code which used it is moved to SpellMgr::LoadDbcDataCorrections
*code which affected dbc data in SpellMgr::LoadSpellCustomAttr is now moved to LoadDbcDataCorrections

src/server/game/Entities/Creature/Creature.h

@@ -29,7 +29,7 @@
 
 #include <list>
 
-struct SpellEntry;
+class SpellInfo;
 
 class CreatureAI;
 class Quest;
@@ -458,9 +458,9 @@ class Creature : public Unit, public GridObject<Creature>
         bool isCanInteractWithBattleMaster(Player* player, bool msg) const;
         bool isCanTrainingAndResetTalentsOf(Player* pPlayer) const;
         bool canCreatureAttack(Unit const *pVictim, bool force = true) const;
-        bool IsImmunedToSpell(SpellEntry const* spellInfo);
+        bool IsImmunedToSpell(SpellInfo const* spellInfo);
                                                             // redefine Unit::IsImmunedToSpell
-        bool IsImmunedToSpellEffect(SpellEntry const* spellInfo, uint32 index) const;
+        bool IsImmunedToSpellEffect(SpellInfo const* spellInfo, uint32 index) const;
                                                             // redefine Unit::IsImmunedToSpellEffect
         bool isElite() const
         {
@@ -570,8 +570,8 @@ class Creature : public Unit, public GridObject<Creature>
         void RemoveLootMode(uint16 lootMode) { m_LootMode &= ~lootMode; }
         void ResetLootMode() { m_LootMode = LOOT_MODE_DEFAULT; }
 
-        SpellEntry const *reachWithSpellAttack(Unit *pVictim);
-        SpellEntry const *reachWithSpellCure(Unit *pVictim);
+        SpellInfo const *reachWithSpellAttack(Unit *pVictim);
+        SpellInfo const *reachWithSpellCure(Unit *pVictim);
 
         uint32 m_spells[CREATURE_MAX_SPELLS];
         CreatureSpellCooldowns m_CreatureSpellCooldowns;