checker: make use of private enum from outside module an error. (#9821)

vlib/os/inode_test.v

@@ -1,42 +1,42 @@
-import os
+module os
 
 const (
 	// tfolder will contain all the temporary files/subfolders made by
 	// the different tests. It would be removed in testsuite_end(), so
 	// individual os tests do not need to clean up after themselves.
-	tfolder = os.join_path(os.temp_dir(), 'v', 'tests', 'inode_test')
+	tfolder = join_path(temp_dir(), 'v', 'tests', 'inode_test')
 )
 
 fn testsuite_begin() {
-	eprintln('testsuite_begin, tfolder = $tfolder')
-	os.rmdir_all(tfolder) or {}
-	assert !os.is_dir(tfolder)
-	os.mkdir_all(tfolder) or { panic(err) }
-	os.chdir(tfolder)
-	assert os.is_dir(tfolder)
+	eprintln('testsuite_begin, tfolder = $os.tfolder')
+	rmdir_all(os.tfolder) or {}
+	assert !is_dir(os.tfolder)
+	mkdir_all(os.tfolder) or { panic(err) }
+	chdir(os.tfolder)
+	assert is_dir(os.tfolder)
 }
 
 fn testsuite_end() {
-	os.chdir(os.wd_at_startup)
-	os.rmdir_all(tfolder) or { panic(err) }
-	assert !os.is_dir(tfolder)
+	chdir(wd_at_startup)
+	rmdir_all(os.tfolder) or { panic(err) }
+	assert !is_dir(os.tfolder)
 }
 
 fn test_inode_file_type() {
 	filename := './test1.txt'
-	mut file := os.open_file(filename, 'w', 0o600) or { return }
+	mut file := open_file(filename, 'w', 0o600) or { return }
 	file.close()
-	mode := os.inode(filename)
-	os.rm(filename) or { panic(err) }
+	mode := inode(filename)
+	rm(filename) or { panic(err) }
 	assert mode.typ == .regular
 }
 
 fn test_inode_file_owner_permission() {
 	filename := './test2.txt'
-	mut file := os.open_file(filename, 'w', 0o600) or { return }
+	mut file := open_file(filename, 'w', 0o600) or { return }
 	file.close()
-	mode := os.inode(filename)
-	os.rm(filename) or {}
+	mode := inode(filename)
+	rm(filename) or {}
 	assert mode.owner.read
 	assert mode.owner.write
 	assert !mode.owner.execute