fix missing SIG_DFL, SIG_IGN, SIG_ERR without posix in signal.h

include/signal.h

@@ -25,15 +25,12 @@ extern "C" {
 
 #include <bits/alltypes.h>
 
+#define SIG_HOLD ((void (*)(int)) 2)
+
 #define SIG_BLOCK     0
 #define SIG_UNBLOCK   1
 #define SIG_SETMASK   2
 
-#define SIG_ERR  ((void (*)(int))-1)
-#define SIG_DFL  ((void (*)(int)) 0)
-#define SIG_IGN  ((void (*)(int)) 1)
-#define SIG_HOLD ((void (*)(int)) 2)
-
 #define SI_ASYNCNL (-60)
 #define SI_TKILL (-6)
 #define SI_SIGIO (-5)
@@ -217,6 +214,10 @@ int sigisemptyset(const sigset_t *);
 
 #include <bits/signal.h>
 
+#define SIG_ERR  ((void (*)(int))-1)
+#define SIG_DFL  ((void (*)(int)) 0)
+#define SIG_IGN  ((void (*)(int)) 1)
+
 typedef int sig_atomic_t;
 
 void (*signal(int, void (*)(int)))(int);