alpha-linux-user: Add correct sigaction constants.

Signed-off-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

linux-user/syscall_defs.h

@@ -336,6 +336,14 @@ int do_sigaction(int sig, const struct target_sigaction *act,
 #if !defined(TARGET_ABI_MIPSN32) && !defined(TARGET_ABI_MIPSN64)
 #define TARGET_SA_RESTORER	0x04000000	/* Only for O32 */
 #endif
+#elif defined(TARGET_ALPHA)
+#define TARGET_SA_ONSTACK	0x00000001
+#define TARGET_SA_RESTART	0x00000002
+#define TARGET_SA_NOCLDSTOP	0x00000004
+#define TARGET_SA_NODEFER	0x00000008
+#define TARGET_SA_RESETHAND	0x00000010
+#define TARGET_SA_NOCLDWAIT	0x00000020 /* not supported yet */
+#define TARGET_SA_SIGINFO	0x00000040
 #else
 #define TARGET_SA_NOCLDSTOP	0x00000001
 #define TARGET_SA_NOCLDWAIT	0x00000002 /* not supported yet */