patch 8.2.3248: Vim9: error message for wrong input uses wrong line number

Problem:    Vim9: error message for wrong input uses wrong line number.
Solution:   Use the line number of the start of the command. (issue #8653)
diff --git a/src/testdir/test_vim9_script.vim b/src/testdir/test_vim9_script.vim
index 4c55eb6..d46299c 100644
--- a/src/testdir/test_vim9_script.vim
+++ b/src/testdir/test_vim9_script.vim
@@ -1223,6 +1223,16 @@
   writefile(import_star_as_lines_dot_space, 'Ximport.vim')
   assert_fails('source Ximport.vim', 'E1074:', '', 1, 'Func')
 
+  var import_func_duplicated =<< trim END
+    vim9script
+    import ExportedInc from './Xexport.vim'
+    import ExportedInc from './Xexport.vim'
+
+    ExportedInc()
+  END
+  writefile(import_func_duplicated, 'Ximport.vim')
+  assert_fails('source Ximport.vim', 'E1073:', '', 3, 'Ximport.vim')
+
   var import_star_as_duplicated =<< trim END
     vim9script
     import * as Export from './Xexport.vim'