test(inttypes): note full-link requirement for standalone runs

tests/test_inttypes.c

@@ -33,6 +33,10 @@
  * owned by a later todo).
  */
 
+/* Link-trap note: strtoimax/strtoumax delegate to strtol/strtoul — standalone
+ * links MUST include src/stdlib/strtox.c + strtox_impl.c (+ strtod.c) or host
+ * glibc silently satisfies them and -f's EINVAL-base checks fail. */
+
 #include <stdint.h>
 
 #include "../include/inttypes.h"