patch 8.2.1403: Vim9: Vim highlighting may fail in cmdline window

Problem:    Vim9: Vim highlighting fails in cmdline window if it uses Vim9
            commands.
Solution:   Allow using :vim9script, :import and :export while in the cmdline
            window. (closes #6656)
diff --git a/src/ex_cmds.h b/src/ex_cmds.h
index c65b956..508ecb8 100644
--- a/src/ex_cmds.h
+++ b/src/ex_cmds.h
@@ -572,7 +572,7 @@
 	EX_RANGE|EX_WHOLEFOLD|EX_BANG|EX_FILE1|EX_ARGOPT|EX_DFLALL|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_LINES),
 EXCMD(CMD_export,	"export",	ex_export,
-	EX_EXTRA|EX_NOTRLCOM|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_exusage,	"exusage",	ex_exusage,
 	EX_TRLBAR,
@@ -698,7 +698,7 @@
 	EX_RANGE|EX_ZEROR|EX_EXTRA|EX_TRLBAR|EX_NOTRLCOM|EX_CTRLV|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_OTHER),
 EXCMD(CMD_import,	"import",	ex_import,
-	EX_EXTRA|EX_NOTRLCOM|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_inoremap,	"inoremap",	ex_map,
 	EX_EXTRA|EX_TRLBAR|EX_NOTRLCOM|EX_CTRLV|EX_CMDWIN|EX_LOCK_OK,
@@ -1670,7 +1670,7 @@
 	EX_RANGE|EX_BANG|EX_NEEDARG|EX_EXTRA|EX_NOTRLCOM|EX_TRLBAR|EX_XFILE,
 	ADDR_OTHER),
 EXCMD(CMD_vim9script,	"vim9script",	ex_vim9script,
-	EX_LOCK_OK,
+	EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_viusage,	"viusage",	ex_viusage,
 	EX_TRLBAR,