add new fcntl.h macros from linux v4.13

for getting/setting write lifetime hints fcntl commands were
added in linux commit c75b1d9421f80f4143e389d2d50ddfc8a28c8c35

added under _GNU_SOURCE || _BSD_SOURCE, since RWH_* life time
hints are not in the POSIX reserved namespace.
diff --git a/include/fcntl.h b/include/fcntl.h
index 0e165ca..6d8edcd 100644
--- a/include/fcntl.h
+++ b/include/fcntl.h
@@ -127,6 +127,18 @@
 #define F_SEAL_GROW	0x0004
 #define F_SEAL_WRITE	0x0008
 
+#define F_GET_RW_HINT		1035
+#define F_SET_RW_HINT		1036
+#define F_GET_FILE_RW_HINT	1037
+#define F_SET_FILE_RW_HINT	1038
+
+#define RWF_WRITE_LIFE_NOT_SET	0
+#define RWH_WRITE_LIFE_NONE	1
+#define RWH_WRITE_LIFE_SHORT	2
+#define RWH_WRITE_LIFE_MEDIUM	3
+#define RWH_WRITE_LIFE_LONG	4
+#define RWH_WRITE_LIFE_EXTREME	5
+
 #define DN_ACCESS	0x00000001
 #define DN_MODIFY	0x00000002
 #define DN_CREATE	0x00000004