more mips bits-header fixes

signal handling was very broken because of this

arch/mips/bits/signal.h

@@ -19,14 +19,18 @@ typedef struct __ucontext {
 } ucontext_t;
 
 #define SA_NOCLDSTOP  1
-#define SA_NOCLDWAIT  2
-#define SA_SIGINFO    4
+#define SA_NOCLDWAIT  0x10000
+#define SA_SIGINFO    8
 #define SA_ONSTACK    0x08000000
 #define SA_RESTART    0x10000000
 #define SA_NODEFER    0x40000000
 #define SA_RESETHAND  0x80000000
 #define SA_RESTORER   0x04000000
 
+#define SIG_BLOCK     1
+#define SIG_UNBLOCK   2
+#define SIG_SETMASK   3
+
 #if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
 struct sigcontext
 {

include/signal.h

@@ -28,9 +28,11 @@ extern "C" {
 
 #define SIG_HOLD ((void (*)(int)) 2)
 
+#ifndef SIG_BLOCK
 #define SIG_BLOCK     0
 #define SIG_UNBLOCK   1
 #define SIG_SETMASK   2
+#endif
 
 #define SI_ASYNCNL (-60)
 #define SI_TKILL (-6)