*: introduce and use FAST_FUNC: regparm on i386, otherwise no-on

text    data     bss     dec     hex filename
 808035     611    6868  815514   c719a busybox_old
 804472     611    6868  811951   c63af busybox_unstripped

networking/dnsd.c

@@ -109,7 +109,7 @@ static void undot(uint8_t * rip)
  * Presently the dot is copied into name without
  * converting to a length/string substring for that label.
  */
-static int getfileentry(FILE * fp, struct dns_entry *s)
+static int getfileentry(FILE *fp, struct dns_entry *s)
 {
 	unsigned int a,b,c,d;
 	char *line, *r, *name;