patch 8.2.2660: Vim9: no error for declaration with trailing text

Problem:    Vim9: no error for declaration with trailing text.
Solution:   Give an error. (closes #8014)
diff --git a/src/testdir/test_vim9_assign.vim b/src/testdir/test_vim9_assign.vim
index f71226e..b9851a7 100644
--- a/src/testdir/test_vim9_assign.vim
+++ b/src/testdir/test_vim9_assign.vim
@@ -1290,6 +1290,8 @@
     other = 1234
     g:other_var = other
 
+    var xyz: string  # comment
+
     # type is inferred
     var s:dict = {['a']: 222}
     def GetDictVal(key: any)
@@ -1365,7 +1367,7 @@
     vim9script
     var 9var: string
   END
-  CheckScriptFailure(lines, 'E475:')
+  CheckScriptFailure(lines, 'E488:')
 
   CheckDefFailure(['var foo.bar = 2'], 'E1087:')
   CheckDefFailure(['var foo[3] = 2'], 'E1087:')
@@ -1617,6 +1619,11 @@
       echo x
   END
   CheckScriptFailureList(lines, ['E1154:', 'E121:'])
+
+  lines =<< trim END
+      var x: string  'string'
+  END
+  CheckDefAndScriptFailure(lines, 'E488:')
 enddef