Remove all usage of the "register" storage class specifier.

coreutils/echo.c

@@ -71,7 +71,7 @@ int bb_echo(int ATTRIBUTE_UNUSED argc, char **argv)
 just_echo:
 #endif
 	while (*argv) {
-		register int c;
+		int c;
 
 		while ((c = *(*argv)++)) {
 			if (c == eflag) {	/* Check for escape seq. */

coreutils/od.c

@@ -35,7 +35,7 @@
 static void
 odoffset(int argc, char ***argvp)
 {
-	register char *num, *p;
+	char *num, *p;
 	int base;
 	char *end;
 

coreutils/test.c

@@ -554,7 +554,7 @@ static void initialize_group_array(void)
 /* Return non-zero if GID is one that we have in our groups list. */
 static int is_a_group_member(gid_t gid)
 {
-	register int i;
+	int i;
 
 	/* Short-circuit if possible, maybe saving a call to getgroups(). */
 	if (gid == getgid() || gid == getegid())

coreutils/tr.c

@@ -178,7 +178,7 @@ static unsigned int expand(const char *arg, char *buffer)
 
 static int complement(char *buffer, int buffer_len)
 {
-	register short i, j, ix;
+	short i, j, ix;
 	char conv[ASCII + 2];
 
 	ix = 0;
@@ -195,7 +195,7 @@ static int complement(char *buffer, int buffer_len)
 
 int tr_main(int argc, char **argv)
 {
-	register unsigned char *ptr;
+	unsigned char *ptr;
 	int output_length=0, input_length;
 	int idx = 1;
 	int i;