patch 8.2.4167: Vim9: error message for old style import

Problem:    Vim9: error message for old style import.
Solution:   Use another error message.  Add a test.

src/errors.h

@@ -2966,8 +2966,7 @@ EXTERN char e_argument_name_shadows_existing_variable_str[]
 	INIT(= N_("E1167: Argument name shadows existing variable: %s"));
 EXTERN char e_argument_already_declared_in_script_str[]
 	INIT(= N_("E1168: Argument already declared in the script: %s"));
-EXTERN char e_import_as_name_not_supported_here[]
+// E1169 unused
-	INIT(= N_("E1169: 'import * as {name}' not supported here"));
 EXTERN char e_cannot_use_hash_curly_to_start_comment[]
 	INIT(= N_("E1170: Cannot use #{ to start a comment"));
 EXTERN char e_missing_end_block[]

src/evalvars.c

@@ -2711,7 +2711,7 @@ eval_variable(
 		else
 		{
 		    if (flags & EVAL_VAR_VERBOSE)
-			emsg(_(e_import_as_name_not_supported_here));
+			semsg(_(e_expected_dot_after_name_str), name);
 		    ret = FAIL;
 		}
 	    }

src/testdir/test_vim9_import.vim

@@ -429,6 +429,19 @@ def Test_import_fails()
       var that = foo
   END
   CheckScriptFailure(lines, 'E1060: Expected dot after name: foo')
+  lines =<< trim END
+      vim9script
+      import './Xfoo.vim' as foo
+      var that: any
+      that += foo
+  END
+  CheckScriptFailure(lines, 'E1060: Expected dot after name: foo')
+  lines =<< trim END
+      vim9script
+      import './Xfoo.vim' as foo
+      foo += 9
+  END
+  CheckScriptFailure(lines, 'E1060: Expected dot after name: foo')
 
   lines =<< trim END
       vim9script

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4167,
 /**/
     4166,
 /**/