Import unmodified NetBSD libc in trunk

This patch imports the unmodified current version of NetBSD libc.
The NetBSD includes are in /nbsd_include, while the libc code itself is 
split between lib/nbsd_libc and common/lib/libc.

lib/nbsd_libc/string/Lint_memset.c

@@ -0,0 +1,18 @@
+/* $NetBSD: Lint_memset.c,v 1.2 2000/06/14 06:49:08 cgd Exp $ */
+
+/*
+ * This file placed in the public domain.
+ * Chris Demetriou, November 5, 1997.
+ */
+
+#include <string.h>
+
+/*ARGSUSED*/
+void *
+memset(b, c, len)
+	void *b;
+	int c;
+	size_t len;
+{
+	return (0);
+}