Introduced target 'atarixl'.

The target 'atarixl' is to be used for Atari XL (and better) machines.
It will disable the OS ROM and enable the Shadow RAM available on
those machine.

Note: This commit is only the inital step towards for this goal that just
replicates the target 'atari' as a starting point!

testcode/lib/ft.c

@@ -24,7 +24,8 @@
 
 extern int getsp(void);  /* is provided in getsp.s */
 
-#ifdef __ATARI__  /* Atari's fd indirection table */
+/* Atari's fd indirection table */
+#if defined(__ATARI__) || defined(__ATARIXL__)
 extern char __fd_index[];
 struct fd_t {
   char usage;
@@ -33,7 +34,7 @@ struct fd_t {
   char flag;
 };
 extern struct fd_t __fd_table[];
-#endif /* #ifdef __ATARI__ */
+#endif
 
 int main(int argc,char **argv)
 {
@@ -73,7 +74,7 @@ int main(int argc,char **argv)
         return(0);
     }
     printf("open success -- handle = $%x, sp = %d\n",fd,csp);
-#ifdef __ATARI__
+#if defined(__ATARI__) || defined(__ATARIXL__)
     printf("fd_index:\n ");
     for (i=0; i<12; i++) printf("%02X ",__fd_index[i]);
     printf("\nfd_table:\n");
@@ -83,7 +84,7 @@ int main(int argc,char **argv)
                __fd_table[i].iocb,
                __fd_table[i].dev);
     }
-#endif /* #ifdef __ATARI__ */
+#endif
     lr = read(fd,buf,16);  /* read first 16 bytes */
     csp = getsp();
     if (lr == -1) {