bpo-40275: Add import_helper submodule in test.support

[shihai1991]

remove the following functions, classes in import_helper:

• import_module(), _ignore_deprecated_imports()
• import_fresh_module(), _save_and_remove_module(), _save_and_block_module()
• unload()
• make_legacy_pyc()
• forget()
• CleanImport
• DirsOnSysPath
• modules_setup(), modules_cleanup()

https://bugs.python.org/issue40275

[shihai1991]

@vstinner hI, victor. Should we leave DirsOnSysPath in support/init.py?
DirOnSysPath have no direct relation with import_module, right?

[vstinner]

DirOnSysPath have no direct relation with import_module, right?

import uses sys.path, no? What's the sys.path purpose otherwise?
https://docs.python.org/dev/library/sys.html#sys.path

[vstinner]

LGTM. But I'm waiting for your feedback on DirsOnSysPath.

[shihai1991]

LGTM. But I'm waiting for your feedback on DirsOnSysPath.

Ok, from the docs: A list of strings that specifies the search path for modules. so it make sense.

[shihai1991]

thanks, victor.