sys/reg apparently only exists on i386 and m68k, so fix the test in
a couple of files
diff --git a/signal.c b/signal.c
index baa3947..5860bf9 100644
--- a/signal.c
+++ b/signal.c
@@ -39,7 +39,7 @@
 #include <signal.h>
 #include <sys/user.h>
 #include <fcntl.h>
-#if __GLIBC__ == 2 && __GLIBC_MINOR__ >= 1
+#if __GLIBC__ == 2 && __GLIBC_MINOR__ >= 1 && (defined(I386) || defined(M68K))
 # include <sys/reg.h>
 #endif