Fixed memory leaks for non-solaris compilers.

lib/check.cpp

@@ -42,7 +42,15 @@ void Check::reportError(const ErrorLogger::ErrorMessage &errmsg)
 {
     std::cout << errmsg.toXML(true, 1) << std::endl;
 }
+
 std::list<Check *> &Check::instances() {
+#ifdef __SVR4
+        // Under Solaris, destructors are called in wrong order which causes a segmentation fault.
+        // This fix ensures pointer remains valid and reachable until program terminates.
         static std::list<Check *> *_instances= new std::list<Check *>;
         return *_instances;
+#else
+        static std::list<Check *> _instances;
+        return _instances;
+#endif
     }