bpo-34726: Fix handling of hash-based pycs in zipimport

[elprans]

Current support for hash-based bytecode files in zipimport is rather
sparse, which leads to test failures when the test suite is ran with
the SOURCE_DATE_EPOCH environment variable set.

This teaches zipimport to handle hash-based pycs properly.

https://bugs.python.org/issue34022

https://bugs.python.org/issue34726

[ncoghlan]

The new tests look good to me, and the changes required to make them pass seem sensible.

[ncoghlan]

Thanks for the PR @elprans!

@serhiy-storchaka @warsaw @brettcannon This looks good to me, but I'd be happier if someone more familiar with the new zipimport code gave it a look before we hit the big green merge button :)

[serhiy-storchaka]

I created bpo-34726, but I'm not sure that any checks for pyc files are needed at all. They slow down import, and we can expect that pyc files in a zip archive are up to date with py files. See bpo-23734.

[serhiy-storchaka]

You need to rebuild frozen modules. Run make regen-importlib.

[elprans]

Done

[vstinner]

test_zipfile_compiled_checked_hash() fails on Python 3.7: we should backport this bugfix to 3.7, no?

[miss-islington]

Thanks @elprans for the PR, and @serhiy-storchaka for merging it 🌮🎉.. I'm working now to backport this PR to: 3.7.
🐍🍒⛏🤖

[miss-islington]

Sorry, @elprans and @serhiy-storchaka, I could not cleanly backport this to 3.7 due to a conflict.
Please backport using cherry_picker on command line.
cherry_picker a6e956bcb0edbfe7f18af9be2215a5326ea6bf05 3.7

[vstinner]

Ah, the change cannot be cherry-picked automatically. Maybe because of the generated file.

[elprans]

@vstinner I'll make a backport PR.

[elprans]

It's a bit more difficult than that. In 3.7 zipimport is in C.

[serhiy-storchaka]

It is easier to skip the test on 3.7.