Patch to bug #472202: Correctly recognize NetBSD before 199712.

Python/dynload_shlib.c

@@ -6,7 +6,9 @@
 
 #include <sys/types.h>
 #include <sys/stat.h>
-#if defined(__NetBSD__) && (NetBSD < 199712)
+#if defined(__NetBSD__)
+#include <sys/param.h>
+#if (NetBSD < 199712)
 #include <nlist.h>
 #include <link.h>
 #define dlerror() "error in dynamic linking"
@@ -15,8 +17,9 @@
 #include <dlfcn.h>
 #endif
 #endif
+#endif /* NetBSD */
 
-#if defined(__OpenBSD__) && !defined(__ELF__)
+#if (defined(__OpenBSD__) || defined(__NetBSD__)) && !defined(__ELF__)
 #define LEAD_UNDERSCORE "_"
 #else
 #define LEAD_UNDERSCORE ""