patch 9.0.1621: FILETYPE_FILE is defined to the same value multiple times

Problem:    FILETYPE_FILE is defined to the same value multiple times.  Same
            for a few similar macros.
Solution:   Define FILETYPE_FILE and others in feature.h only
diff --git a/src/feature.h b/src/feature.h
index ba61fa2..ca180dd 100644
--- a/src/feature.h
+++ b/src/feature.h
@@ -715,19 +715,31 @@
 
 /*
  * File names for:
- * FILETYPE_FILE	switch on file type detection
- * FTPLUGIN_FILE	switch on loading filetype plugin files
- * INDENT_FILE		switch on loading indent files
- * FTOFF_FILE		switch off file type detection
- * FTPLUGOF_FILE	switch off loading settings files
- * INDOFF_FILE		switch off loading indent files
+ * FILETYPE_FILE	used for file type detection
+ * FTPLUGIN_FILE	used for loading filetype plugin files
+ * INDENT_FILE		used for loading indent files
+ * FTOFF_FILE		used for file type detection
+ * FTPLUGOF_FILE	used for loading settings files
+ * INDOFF_FILE		used for loading indent files
  */
-// # define FILETYPE_FILE	"filetype.vim"
-// # define FTPLUGIN_FILE	"ftplugin.vim"
-// # define INDENT_FILE		"indent.vim"
-// # define FTOFF_FILE		"ftoff.vim"
-// # define FTPLUGOF_FILE	"ftplugof.vim"
-// # define INDOFF_FILE		"indoff.vim"
+#ifndef FILETYPE_FILE
+# define FILETYPE_FILE		"filetype.vim"
+#endif
+#ifndef FTPLUGIN_FILE
+# define FTPLUGIN_FILE		"ftplugin.vim"
+#endif
+#ifndef INDENT_FILE
+# define INDENT_FILE		"indent.vim"
+#endif
+#ifndef FTOFF_FILE
+# define FTOFF_FILE		"ftoff.vim"
+#endif
+#ifndef FTPLUGOF_FILE
+# define FTPLUGOF_FILE		"ftplugof.vim"
+#endif
+#ifndef INDOFF_FILE
+# define INDOFF_FILE		"indoff.vim"
+#endif
 
 /*
  * SYS_MENU_FILE	Name of the default menu.vim file.
diff --git a/src/os_amiga.h b/src/os_amiga.h
index 98f3cff..5741713 100644
--- a/src/os_amiga.h
+++ b/src/os_amiga.h
@@ -129,24 +129,6 @@
 #ifndef DFLT_HELPFILE
 # define DFLT_HELPFILE	"$VIMRUNTIME/doc/help.txt"
 #endif
-#ifndef FILETYPE_FILE
-# define FILETYPE_FILE	"filetype.vim"
-#endif
-#ifndef FTPLUGIN_FILE
-# define FTPLUGIN_FILE	"ftplugin.vim"
-#endif
-#ifndef INDENT_FILE
-# define INDENT_FILE	"indent.vim"
-#endif
-#ifndef FTOFF_FILE
-# define FTOFF_FILE	"ftoff.vim"
-#endif
-#ifndef FTPLUGOF_FILE
-# define FTPLUGOF_FILE	"ftplugof.vim"
-#endif
-#ifndef INDOFF_FILE
-# define INDOFF_FILE	"indoff.vim"
-#endif
 #ifndef SYNTAX_FNAME
 # define SYNTAX_FNAME	"$VIMRUNTIME/syntax/%s.vim"
 #endif
diff --git a/src/os_dos.h b/src/os_dos.h
index 1d67ab8..f1fcbe6 100644
--- a/src/os_dos.h
+++ b/src/os_dos.h
@@ -88,25 +88,6 @@
 # define DFLT_HELPFILE	"$VIMRUNTIME\\doc\\help.txt"
 #endif
 
-#ifndef FILETYPE_FILE
-# define FILETYPE_FILE	"filetype.vim"
-#endif
-#ifndef FTPLUGIN_FILE
-# define FTPLUGIN_FILE	"ftplugin.vim"
-#endif
-#ifndef INDENT_FILE
-# define INDENT_FILE	"indent.vim"
-#endif
-#ifndef FTOFF_FILE
-# define FTOFF_FILE	"ftoff.vim"
-#endif
-#ifndef FTPLUGOF_FILE
-# define FTPLUGOF_FILE	"ftplugof.vim"
-#endif
-#ifndef INDOFF_FILE
-# define INDOFF_FILE	"indoff.vim"
-#endif
-
 #ifndef SYNTAX_FNAME
 # define SYNTAX_FNAME	"$VIMRUNTIME\\syntax\\%s.vim"
 #endif
diff --git a/src/os_mac.h b/src/os_mac.h
index 17e9478..34fe1f1 100644
--- a/src/os_mac.h
+++ b/src/os_mac.h
@@ -145,25 +145,6 @@
 # define DFLT_HELPFILE	"$VIMRUNTIME/doc/help.txt"
 #endif
 
-#ifndef FILETYPE_FILE
-# define FILETYPE_FILE	"filetype.vim"
-#endif
-#ifndef FTPLUGIN_FILE
-# define FTPLUGIN_FILE	"ftplugin.vim"
-#endif
-#ifndef INDENT_FILE
-# define INDENT_FILE	"indent.vim"
-#endif
-#ifndef FTOFF_FILE
-# define FTOFF_FILE	"ftoff.vim"
-#endif
-#ifndef FTPLUGOF_FILE
-# define FTPLUGOF_FILE	"ftplugof.vim"
-#endif
-#ifndef INDOFF_FILE
-# define INDOFF_FILE	"indoff.vim"
-#endif
-
 #ifndef SYNTAX_FNAME
 # define SYNTAX_FNAME	"$VIMRUNTIME/syntax/%s.vim"
 #endif
diff --git a/src/os_unix.h b/src/os_unix.h
index c03e293..4c77e15 100644
--- a/src/os_unix.h
+++ b/src/os_unix.h
@@ -216,24 +216,6 @@
 #ifndef DFLT_HELPFILE
 # define DFLT_HELPFILE	"$VIMRUNTIME/doc/help.txt"
 #endif
-#ifndef FILETYPE_FILE
-# define FILETYPE_FILE	"filetype.vim"
-#endif
-#ifndef FTPLUGIN_FILE
-# define FTPLUGIN_FILE	"ftplugin.vim"
-#endif
-#ifndef INDENT_FILE
-# define INDENT_FILE	"indent.vim"
-#endif
-#ifndef FTOFF_FILE
-# define FTOFF_FILE	"ftoff.vim"
-#endif
-#ifndef FTPLUGOF_FILE
-# define FTPLUGOF_FILE	"ftplugof.vim"
-#endif
-#ifndef INDOFF_FILE
-# define INDOFF_FILE	"indoff.vim"
-#endif
 #ifndef SYS_MENU_FILE
 # define SYS_MENU_FILE	"$VIMRUNTIME/menu.vim"
 #endif
diff --git a/src/version.c b/src/version.c
index bad9e54..e5cb446 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1621,
+/**/
     1620,
 /**/
     1619,