patch 8.2.5025: Vim9: a few lines not covered by tests

Problem:    Vim9: a few lines not covered by tests.
Solution:   Add a few tests.
diff --git a/src/testdir/test_vim9_assign.vim b/src/testdir/test_vim9_assign.vim
index a13e370..b0ce398 100644
--- a/src/testdir/test_vim9_assign.vim
+++ b/src/testdir/test_vim9_assign.vim
@@ -213,6 +213,8 @@
   v9.CheckDefFailure(['var s:var = 123'], 'E1101:')
   v9.CheckDefFailure(['var s:var: number'], 'E1101:')
 
+  v9.CheckDefAndScriptFailure(['var $VAR: number'], ['E1016:', 'E475:'])
+
   lines =<< trim END
     vim9script
     def SomeFunc()
diff --git a/src/testdir/test_vim9_import.vim b/src/testdir/test_vim9_import.vim
index 159e51b..415a7a9 100644
--- a/src/testdir/test_vim9_import.vim
+++ b/src/testdir/test_vim9_import.vim
@@ -312,6 +312,14 @@
   writefile(import_no_as_lines, 'Ximport.vim')
   assert_fails('source Ximport.vim', 'E488:', '', 2, 'Ximport.vim')
 
+  # trailing starts with "as"
+  var import_bad_as_lines =<< trim END
+    vim9script
+    import './Xexport.vim' asname
+  END
+  writefile(import_no_as_lines, 'Ximport.vim')
+  assert_fails('source Ximport.vim', 'E488:', '', 2, 'Ximport.vim')
+
   var import_invalid_string_lines =<< trim END
     vim9script
     import Xexport.vim
@@ -396,6 +404,27 @@
   delete('Xvim9_script')
 enddef
 
+def Test_import_very_long_name()
+  var lines =<< trim END
+      vim9script
+
+      export var verylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongname = 'asdf'
+  END
+  writefile(lines, 'Xverylong.vim')
+
+  lines =<< trim END
+      vim9script
+      import './Xverylong.vim'
+
+      g:result = Xverylong.verylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongnameverylongname
+  END
+  v9.CheckScriptSuccess(lines)
+  assert_equal('asdf', g:result)
+
+  delete('Xverylong.vim')
+  unlet g:result
+enddef
+
 def Test_import_funcref()
   var lines =<< trim END
       vim9script
@@ -712,6 +741,16 @@
   nunmap <F3>
 enddef
 
+def Test_autoload_import_var()
+  # variable name starts with "autoload"
+  var lines =<< trim END
+      vim9script
+      var autoloaded = "Xtest.vim"
+      import autoloaded
+  END
+  v9.CheckScriptFailure(lines, 'E1053: Could not import "Xtest.vim')
+enddef
+
 def Test_use_autoload_import_in_mapping()
   var lines =<< trim END
       vim9script