add defines for number of sigset_t bytes syscalls expect

yet another gratuitous mips incompatibility...

arch/arm/bits/syscall.h

@@ -3,6 +3,8 @@
 ((union { long long ll; long l[2]; }){ .ll = x }).l[1]
 #define __SYSCALL_LL_O(x) 0, __SYSCALL_LL_E((x))
 
+#define __SYSCALL_SSLEN 8
+
 long (__syscall)(long, ...);
 
 static inline long __syscall0(long n)

arch/i386/bits/syscall.h

@@ -3,6 +3,8 @@
 ((union { long long ll; long l[2]; }){ .ll = x }).l[1]
 #define __SYSCALL_LL_O(x) __SYSCALL_LL_E((x))
 
+#define __SYSCALL_SSLEN 8
+
 static inline long __syscall0(long __n)
 {
 	unsigned long __ret;

arch/mips/bits/syscall.h

@@ -3,6 +3,8 @@
 ((union { long long ll; long l[2]; }){ .ll = x }).l[1]
 #define __SYSCALL_LL_O(x) 0, __SYSCALL_LL_E((x))
 
+#define __SYSCALL_SSLEN 16
+
 long (__syscall)(long, ...);
 
 static inline long __syscall0(long n)

arch/x86_64/bits/syscall.h

@@ -1,6 +1,8 @@
 #define __SYSCALL_LL_E(x) (x)
 #define __SYSCALL_LL_O(x) (x)
 
+#define __SYSCALL_SSLEN 8
+
 static inline long __syscall0(long __n)
 {
 	unsigned long __ret;