add F_SETSIG and F_GETSIG (linux specific) to fcntl.h

F_* is in the reserved namespace so no feature test is needed

arch/arm/bits/fcntl.h

@@ -25,6 +25,8 @@
 
 #define F_SETOWN 8
 #define F_GETOWN 9
+#define F_SETSIG 10
+#define F_GETSIG 11
 
 #define F_GETLK 12
 #define F_SETLK 13

arch/i386/bits/fcntl.h

@@ -25,6 +25,8 @@
 
 #define F_SETOWN 8
 #define F_GETOWN 9
+#define F_SETSIG 10
+#define F_GETSIG 11
 
 #define F_GETLK 12
 #define F_SETLK 13

arch/x86_64/bits/fcntl.h

@@ -25,6 +25,8 @@
 
 #define F_SETOWN 8
 #define F_GETOWN 9
+#define F_SETSIG 10
+#define F_GETSIG 11
 
 #define F_GETLK 5
 #define F_SETLK 6