(svn r18809) -Codechange/Cleanup: remove unneeded headers from some files, if a header require a header make it include that header

src/ai/ai_instance.hpp

@@ -12,6 +12,8 @@
 #ifndef AI_INSTANCE_HPP
 #define AI_INSTANCE_HPP
 
+#include <squirrel.h>
+
 /**
  * The callback function when an AI suspends.
  */