Move cstdlib include with others

Author: jarzec

include/cpp2util.h

@@ -261,6 +261,7 @@
     #include <cstddef>
     #include <cstdint>
     #include <cstdio>
+    #include <cstdlib>
     #ifndef CPP2_NO_EXCEPTIONS
         #include <exception>
     #endif
@@ -301,7 +302,6 @@
     #include <vector>
 #endif
 
-#include <cstdlib>
 // #ifndef EXIT_FAILURE
 //     #define EXIT_FAILURE 1
 // #endif