Core/Misc: make clang 6.0 happy

src/common/Collision/Models/GameObjectModel.h

@@ -47,6 +47,7 @@ public:
     virtual float GetOrientation() const { return 0.0f; }
     virtual float GetScale() const { return 1.0f; }
     virtual void DebugVisualizeCorner(G3D::Vector3 const& /*corner*/) const { }
+    virtual ~GameObjectModelOwnerBase() { }
 };
 
 class TC_COMMON_API GameObjectModel /*, public Intersectable*/

src/common/Logging/Log.cpp

@@ -258,7 +258,7 @@ std::string Log::GetTimestampStr()
 bool Log::SetLogLevel(std::string const& name, const char* newLevelc, bool isLogger /* = true */)
 {
     LogLevel newLevel = LogLevel(atoi(newLevelc));
-    if (newLevel < 0)
+    if (static_cast<int>(newLevel) < 0)
         return false;
 
     if (isLogger)

src/server/game/Entities/Object/ObjectGuid.h

@@ -318,6 +318,7 @@ class TC_GAME_API ObjectGuidGeneratorBase
         virtual void Set(ObjectGuid::LowType val) { _nextGuid = val; }
         virtual ObjectGuid::LowType Generate() = 0;
         ObjectGuid::LowType GetNextAfterMaxUsed() const { return _nextGuid; }
+        virtual ~ObjectGuidGeneratorBase() { }
 
     protected:
         static void HandleCounterOverflow(HighGuid high);

src/server/game/Handlers/QueryHandler.cpp

@@ -103,7 +103,7 @@ void WorldSession::HandleCreatureQueryOpcode(WorldPacket& recvData)
         Title = creatureInfo->Title;
 
         LocaleConstant locale = GetSessionDbLocaleIndex();
-        if (locale >= 0)
+        if (static_cast<int>(locale >= 0));
         {
             if (CreatureLocale const* creatureLocale = sObjectMgr->GetCreatureLocale(entry))
             {