old sigsuspend variants in kernel/signal.c

conditional on OLD_SIGSUSPEND/OLD_SIGSUSPEND3, depending on which
variety of that fossil is needed.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/Kconfig b/arch/Kconfig
index c612b5c..6b1df95 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -387,4 +387,14 @@
 	help
 	  Architecture has unusual rt_sigaction(2) arguments
 
+config OLD_SIGSUSPEND
+	bool
+	help
+	  Architecture has old sigsuspend(2) syscall, of one-argument variety
+
+config OLD_SIGSUSPEND3
+	bool
+	help
+	  Even weirder antique ABI - three-argument sigsuspend(2)
+
 source "kernel/gcov/Kconfig"