turn off variable tracking through turning off optimization for GCC 4.4 and later

This will avoid a difficult to interpret warning and in
addition speed up compilation of this one file by avoiding
to try to optimize something, that needs no optimization.

src/lammps.cpp

@@ -53,6 +53,12 @@
 #include "memory.h"
 #include "error.h"
 
+#if defined(__GNUC__) && !defined(__clang__) && !defined(__INTEL_COMPILER)
+#if (__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 4))
+#pragma GCC optimize ("O0")
+#endif
+#endif
+
 #include "lmpinstalledpkgs.h"
 #include "lmpgitversion.h"