Core/Build: Provide an interface target for game

* Increases the build time because dependent projects can build
  without waiting for the game project.

(cherry picked from commit ff8a54ab92)

src/server/game/CMakeLists.txt

@@ -23,27 +23,36 @@ GroupSources(${CMAKE_CURRENT_SOURCE_DIR})
 
 add_definitions(-DTRINITY_API_EXPORT_GAME)
 
-add_library(game
-  ${PRIVATE_PCH_SOURCE}
-  ${PRIVATE_SOURCES}
-)
-
 CollectIncludeDirectories(
   ${CMAKE_CURRENT_SOURCE_DIR}
   PUBLIC_INCLUDES
   # Exclude
   ${CMAKE_CURRENT_SOURCE_DIR}/PrecompiledHeaders)
 
+# Provide an interface target for the game project to allow
+# dependent projects to build meanwhile.
+add_library(game-interface INTERFACE)
+
+target_include_directories(game-interface
+  INTERFACE
+    ${PUBLIC_INCLUDES})
+
+target_link_libraries(game-interface
+  INTERFACE
+    shared
+    Detour)
+
+add_library(game
+  ${PRIVATE_PCH_SOURCE}
+  ${PRIVATE_SOURCES})
+
 target_include_directories(game
-  PUBLIC
-    ${PUBLIC_INCLUDES}
   PRIVATE
     ${CMAKE_CURRENT_BINARY_DIR})
 
 target_link_libraries(game
   PUBLIC
-    shared
-    Detour
+    game-interface
   PRIVATE
     efsw)
 

src/server/scripts/CMakeLists.txt

@@ -206,7 +206,7 @@ add_library(scripts STATIC
 
 target_link_libraries(scripts
   PUBLIC
-    game)
+    game-interface)
 
 target_include_directories(scripts
   PUBLIC

src/server/worldserver/CMakeLists.txt

@@ -48,6 +48,7 @@ set_target_properties(worldserver PROPERTIES LINK_FLAGS "${worldserver_LINK_FLAG
 target_link_libraries(worldserver
   PUBLIC
     scripts
+    game
     readline)
 
 CollectIncludeDirectories(