Add support for HP-UX

tested on: HP-UX 11.31 ia64,
               gcc 4.7.1(HP AllianceOne version)
               gcc 4.2.3(http://hpux.connect.org.uk)
	       HP C/aC++

HP-UX defaults to use LP32 and it treats long as 32 bit (= 4 bytes).
This build forces LP64 for treating long as 64 bit.

crypto/compat/arc4random.h

@@ -6,6 +6,9 @@
 #if defined(__FreeBSD__)
 #include "arc4random_freebsd.h"
 
+#elif defined(__hpux)
+#include "arc4random_hpux.h"
+
 #elif defined(__linux__)
 #include "arc4random_linux.h"