update s390 syscalls, add script
diff --git a/sysdeps/linux-gnu/README b/sysdeps/linux-gnu/README
index 2a7a59a..a8bc8ee 100644
--- a/sysdeps/linux-gnu/README
+++ b/sysdeps/linux-gnu/README
@@ -6,6 +6,8 @@
It can be done automatically with "mksignalent" for all the
architectures. (linux-2.2.12)
+* s390 uses mksyscallent_s390, rather than mksyscallent
+
* NOTE: This does not currently work for cross-compilers; Maybe
I should guess the architecture using `gcc -print-libgcc-file-name'
instead of `uname -m' (or even better, use the value returned by autoconf)