Add private __getenv_reentrant()

A reentrant variant of getenv().

headers/private/libroot/stdlib_private.h

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2013, Ingo Weinhold, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _LIBROOT_STDLIB_PRIVATE_H
+#define _LIBROOT_STDLIB_PRIVATE_H
+
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+
+__BEGIN_DECLS
+
+
+ssize_t	__getenv_reentrant(const char* name, char* buffer,
+			size_t bufferSize);
+
+
+__END_DECLS
+
+
+#endif	/* _LIBROOT_STDLIB_PRIVATE_H */