Check EXIT_FAILURE in cstdlib

Author: jarzec

include/cpp2util.h

@@ -301,10 +301,10 @@
     #include <vector>
 #endif
 
-// Missing with MSVC
-#ifndef EXIT_FAILURE
-    #define EXIT_FAILURE 1
-#endif
+#include <cstdlib>
+// #ifndef EXIT_FAILURE
+//     #define EXIT_FAILURE 1
+// #endif
 
 //  cpp2util.h uses signed integer types for indices and container sizes
 //  so disable clang signed-to-unsigned conversion warnings in this header.