patch 9.1.0966: Vim9: :enum command can be shortened

Problem:  Vim9: :enum command can be shortened
Solution: prevent shortening of :enum command by adding the EX_WHOLE
          flag to command definition (h-east)

closes: #16305

Signed-off-by: h-east <h.east.727@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/ex_cmds.h

@@ -597,7 +597,7 @@ EXCMD(CMD_enew,		"enew",		ex_edit,
 	EX_BANG|EX_TRLBAR,
 	ADDR_NONE),
 EXCMD(CMD_enum,		"enum",		ex_class,
-	EX_EXTRA|EX_CMDWIN|EX_LOCK_OK|EX_EXPORT,
+	EX_EXTRA|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE|EX_EXPORT,
 	ADDR_NONE),
 EXCMD(CMD_eval,		"eval",		ex_eval,
 	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,

src/testdir/test_vim9_enum.vim

@@ -44,6 +44,14 @@ def Test_enum_parse()
   END
   v9.CheckSourceFailure(lines, 'E492: Not an editor command: enums Something', 2)
 
+  # The complete "enum" should be specified.
+  lines =<< trim END
+    vim9script
+    enu Something
+    endenum
+  END
+  v9.CheckSourceFailure(lines, 'E1065: Command cannot be shortened: enu', 2)
+
   # The complete "endenum" should be specified.
   lines =<< trim END
     vim9script

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    966,
 /**/
     965,
 /**/