malloc: Extend malloc function hiding to tst-reallocarray (BZ #32366)

clang 20 optimize out reallocarray.

Reviewed-by: Sam James <sam@gentoo.org>

malloc/tst-reallocarray.c

@@ -21,6 +21,7 @@
 #include <string.h>
 #include <support/check.h>
 #include <libc-diag.h>
+#include "tst-malloc-aux.h"
 
 static void *
 reallocarray_nowarn (void *ptr, size_t nmemb, size_t size)