patch 8.1.0932: Farsi support is outdated and unused

Problem:    Farsi support is outdated and unused.
Solution:   Delete the Farsi support.

src/main.c

@@ -535,17 +535,6 @@ vim_main2(void)
     if (params.no_swap_file)
 	p_uc = 0;
 
-#ifdef FEAT_FKMAP
-    if (curwin->w_p_rl && p_altkeymap)
-    {
-	p_hkmap = FALSE;	/* Reset the Hebrew keymap mode */
-# ifdef FEAT_ARABIC
-	curwin->w_p_arab = FALSE; /* Reset the Arabic keymap mode */
-# endif
-	p_fkmap = TRUE;		/* Set the Farsi keymap mode */
-    }
-#endif
-
 #ifdef FEAT_GUI
     if (gui.starting)
     {
@@ -2025,14 +2014,9 @@ command_line_scan(mparm_T *parmp)
 		main_start_gui();
 		break;
 
-	    case 'F':		/* "-F" start in Farsi mode: rl + fkmap set */
-#ifdef FEAT_FKMAP
-		p_fkmap = TRUE;
-		set_option_value((char_u *)"rl", 1L, NULL, 0);
-#else
+	    case 'F':		/* "-F" was for Farsi mode */
 		mch_errmsg(_(e_nofarsi));
 		mch_exit(2);
-#endif
 		break;
 
 	    case '?':		/* "-?" give help message (for MS-Windows) */
@@ -3350,9 +3334,6 @@ usage(void)
 #endif
 #ifdef FEAT_RIGHTLEFT
     main_msg(_("-H\t\t\tStart in Hebrew mode"));
-#endif
-#ifdef FEAT_FKMAP
-    main_msg(_("-F\t\t\tStart in Farsi mode"));
 #endif
     main_msg(_("-T <terminal>\tSet terminal type to <terminal>"));
     main_msg(_("--not-a-term\t\tSkip warning for input/output not being a terminal"));