Add some missing libc functions: setenv, unsetenv, strdup.

--HG--
branch : dtrg-videocore
rename : lang/cem/libcc.ansi/stdlib/getenv.c => lang/cem/libcc.ansi/stdlib/setenv.c
rename : lang/cem/libcc.ansi/string/strlen.c => lang/cem/libcc.ansi/string/strdup.c

lang/cem/libcc.ansi/string/strdup.c

@@ -0,0 +1,17 @@
+/*
+ * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
+ * See the copyright notice in the ACK home directory, in the file "Copyright".
+ */
+/* $Id$ */
+
+#include	<string.h>
+
+char*
+strdup(const char *s)
+{
+	int len = strlen(s);
+	char *p = malloc(len+1);
+	if (p)
+		memcpy(p, s, len+1);
+	return p;
+}