Provide definitions that are missing on Solaris.

This patch should be sent upstream.

--- rtorrent-0.9.6/src/utils/directory.h.orig	2015-09-07 13:12:40.000000000 -0700

+++ rtorrent-0.9.6/src/utils/directory.h	2015-09-16 09:22:02.113830073 -0700

@@ -41,6 +41,32 @@

 #include <vector>

 #include <inttypes.h>

+#if defined(sun) || defined(__sun) || defined(__sun__)

+extern "C" {

+  enum

+  {

+    DT_UNKNOWN = 0,

+#define DT_UNKNOWN     DT_UNKNOWN

+    DT_FIFO = 1,

+#define DT_FIFO        DT_FIFO

+    DT_CHR = 2,

+#define DT_CHR         DT_CHR

+    DT_DIR = 4,

+#define DT_DIR         DT_DIR

+    DT_BLK = 6,

+#define DT_BLK         DT_BLK

+    DT_REG = 8,

+#define DT_REG         DT_REG

+    DT_LNK = 10,

+#define DT_LNK         DT_LNK

+    DT_SOCK = 12,

+#define DT_SOCK        DT_SOCK

+    DT_WHT = 14

+#define DT_WHT         DT_WHT

+  };

+};

+#endif

+

 namespace utils {

 struct directory_entry {