Provide glibc-compatible SYS_* aliases for the __NR_* constants.

This helps us remove another external/strace bionic hack.

Change-Id: I3e82c0d2fd27e479be98f096e05b666fd16f8eb3
diff --git a/libc/include/sys/linux-syscalls.h b/libc/include/sys/linux-syscalls.h
index 738d9e8..2e6421f 100644
--- a/libc/include/sys/linux-syscalls.h
+++ b/libc/include/sys/linux-syscalls.h
@@ -1,4 +1,4 @@
-/* auto-generated by gensyscalls.py, do not touch */
+/* Auto-generated by gensyscalls.py; do not edit. */
 #ifndef _BIONIC_LINUX_SYSCALLS_H_
 #define _BIONIC_LINUX_SYSCALLS_H_