add some missed statics on constant objects.

fix few #ifndef ENABLE_xxx

# size busybox_old busybox_unstripped
   text    data     bss     dec     hex filename
 677152    2920   18208  698280   aa7a8 busybox_old
 676420    2920   18208  697548   aa4cc busybox_unstripped

coreutils/tr.c

@@ -84,7 +84,7 @@ static unsigned int expand(const char *arg, char *buffer)
 	unsigned i; /* XXX: FIXME: use unsigned char? */
 	unsigned char ac;
 #define CLO ":]"
-	const char * const classes[] = {
+	static const char * const classes[] = {
 		"alpha"CLO, "alnum"CLO, "digit"CLO, "lower"CLO, "upper"CLO, "space"CLO,
 		"blank"CLO, "punct"CLO, "cntrl"CLO, NULL
 	};