patch 9.0.0657: too many #ifdefs

Problem:    Too many #ifdefs.
Solution:   Graduate the +cmdwin feature.  Now the tiny and small builds are
            equal, drop the small build.  (Martin Tournoij, closes #11268)
diff --git a/src/errors.h b/src/errors.h
index 3fa2db1..5a976de 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -15,10 +15,8 @@
 
 EXTERN char e_backslash_should_be_followed_by[]
 	INIT(= N_("E10: \\ should be followed by /, ? or &"));
-#ifdef FEAT_CMDWIN
 EXTERN char e_invalid_in_cmdline_window[]
 	INIT(= N_("E11: Invalid in command-line window; :q<CR> closes the window"));
-#endif
 EXTERN char e_command_not_allowed_from_vimrc_in_current_dir_or_tag_search[]
 	INIT(= N_("E12: Command not allowed from exrc/vimrc in current dir or tag search"));
 EXTERN char e_file_exists[]
@@ -461,10 +459,8 @@
 EXTERN char e_cannot_set_language_to_str[]
 	INIT(= N_("E197: Cannot set language to \"%s\""));
 // E198 unused
-#ifdef FEAT_CMDWIN
 EXTERN char e_active_window_or_buffer_deleted[]
 	INIT(= N_("E199: Active window or buffer deleted"));
-#endif
 EXTERN char e_readpre_autocommands_made_file_unreadable[]
 	INIT(= N_("E200: *ReadPre autocommands made the file unreadable"));
 EXTERN char e_readpre_autocommands_must_not_change_current_buffer[]
@@ -3012,7 +3008,7 @@
 #endif
 EXTERN char e_failed_to_source_defaults[]
 	INIT(= N_("E1187: Failed to source defaults.vim"));
-#if defined(FEAT_TERMINAL) && defined(FEAT_CMDWIN)
+#if defined(FEAT_TERMINAL)
 EXTERN char e_cannot_open_terminal_from_command_line_window[]
 	INIT(= N_("E1188: Cannot open a terminal from the command line window"));
 #endif
@@ -3291,10 +3287,8 @@
 EXTERN char e_invalid_argument_nr[]
 	INIT(= N_("E1291: Invalid argument: %ld"));
 #endif
-#ifdef FEAT_CMDWIN
 EXTERN char e_cmdline_window_already_open[]
 	INIT(= N_("E1292: Command-line window is already open"));
-#endif
 #ifdef FEAT_PROP_POPUP
 EXTERN char e_cannot_use_negative_id_after_adding_textprop_with_text[]
 	INIT(= N_("E1293: Cannot use a negative id after adding a textprop with text"));