Revert "explicit aspect activation"

Unfortunately, this does not (yet) work as advertised.  I need to fight another
round of CMake battles before retrying.  Reverting to previous state for now.

This reverts r1753.

git-svn-id: https://www4.informatik.uni-erlangen.de/i4svn/danceos/trunk/devel/fail@1767 8c4709b5-6ec9-48aa-a5cd-a96041d1645a

src/core/sal/gem5/Gem5Listener.ah

@@ -1,6 +1,11 @@
 #ifndef __GEM5LISTENER_AH__
   #define __GEM5LISTENER_AH__
 
+#include "config/VariantConfig.hpp"
+#include "config/FailConfig.hpp"
+
+#if defined(BUILD_GEM5) && defined(CONFIG_EVENT_BREAKPOINTS)
+
 #include "Gem5PCEvents.hpp"
 #include "sim/system.hh"
 
@@ -30,4 +35,5 @@ aspect Gem5Listener
 	};
 };
 
+#endif // BUILD_GEM5 && CONFIG_EVENT_BREAKPOINTS
 #endif // __GEM5LISTENER_AH__