*: 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

diff --git a/libbb/llist.c b/libbb/llist.c
index 4b3971b..094c652 100644
--- a/libbb/llist.c
+++ b/libbb/llist.c
@@ -13,7 +13,7 @@
 #include "libbb.h"
 
 /* Add data to the start of the linked list.  */
-void llist_add_to(llist_t **old_head, void *data)
+void FAST_FUNC llist_add_to(llist_t **old_head, void *data)
 {
 	llist_t *new_head = xmalloc(sizeof(llist_t));
 
@@ -23,7 +23,7 @@
 }
 
 /* Add data to the end of the linked list.  */
-void llist_add_to_end(llist_t **list_head, void *data)
+void FAST_FUNC llist_add_to_end(llist_t **list_head, void *data)
 {
 	llist_t *new_item = xmalloc(sizeof(llist_t));
 
@@ -42,7 +42,7 @@
 }
 
 /* Remove first element from the list and return it */
-void *llist_pop(llist_t **head)
+void* FAST_FUNC llist_pop(llist_t **head)
 {
 	void *data, *next;
 
@@ -58,7 +58,7 @@
 }
 
 /* Unlink arbitrary given element from the list */
-void llist_unlink(llist_t **head, llist_t *elm)
+void FAST_FUNC llist_unlink(llist_t **head, llist_t *elm)
 {
 	llist_t *crt;
 
@@ -80,7 +80,7 @@
 
 /* Recursively free all elements in the linked list.  If freeit != NULL
  * call it on each datum in the list */
-void llist_free(llist_t *elm, void (*freeit) (void *data))
+void FAST_FUNC llist_free(llist_t *elm, void (*freeit) (void *data))
 {
 	while (elm) {
 		void *data = llist_pop(&elm);
@@ -92,7 +92,7 @@
 
 #ifdef UNUSED
 /* Reverse list order. */
-llist_t *llist_rev(llist_t *list)
+llist_t* FAST_FUNC llist_rev(llist_t *list)
 {
 	llist_t *rev = NULL;