Core/Game: Move singleton instances into compilation units

* Fixes issues when building shared libraries
  (prevents gcc and clang from providing several instance)

(cherry picked from commit 329225b40d110bed634f8cd0a1ab5c6dc7bbbdd1)

1 files changed, 6 insertions, 0 deletions

diff --git a/src/server/game/Calendar/CalendarMgr.cpp b/src/server/game/Calendar/CalendarMgr.cpp
index 9d50b290c5e..b27aac7876a 100644
--- a/src/server/game/Calendar/CalendarMgr.cpp
+++ b/src/server/game/Calendar/CalendarMgr.cpp
@@ -45,6 +45,12 @@ CalendarMgr::~CalendarMgr()
             delete *itr2;
 }
 
+CalendarMgr* CalendarMgr::instance()
+{
+    static CalendarMgr instance;
+    return &instance;
+}
+
 void CalendarMgr::LoadFromDB()
 {
     uint32 count = 0;