avoid gcc warnings about unused macro definitions * lib/readtokens.c (STREQ): Remove unused definition. * lib/xmalloc.c (SIZE_MAX): Likewise. * lib/openat-die.c (N_): Likewise. * lib/mountlist.c (SIZE_MAX): Remove definition. Instead, include <stdint.h>. * lib/readutmp.c: Likewise. * modules/readutmp (Depends-on): Add stdint. * modules/mountlist (Depends-on): Add stdint. * lib/userspec.c (ISDIGIT): Move definition into #if block where used.

--- a/lib/readutmp.c
+++ b/lib/readutmp.c
@@ -31,6 +31,7 @@
 #include <stdbool.h>
 #include <string.h>
 #include <stdlib.h>
+#include <stdint.h>
 
 #include "xalloc.h"
 
@@ -38,10 +39,6 @@
 # include "unlocked-io.h"
 #endif
 
-#ifndef SIZE_MAX
-# define SIZE_MAX ((size_t) -1)
-#endif
-
 /* Copy UT->ut_name into storage obtained from malloc.  Then remove any
    trailing spaces from the copy, NUL terminate it, and return the copy.  */