Update copyright date

[panzarino]

New copyright date

Happy new year!

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @nrc (or someone else) soon.

If any changes to this PR are deemed necessary, please add them as extra commits. This ensures that the reviewer can see what has changed since they last reviewed the code. Due to the way GitHub handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed. Large or tricky changes may require several passes of review and changes.

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[eddyb]

AFAIK we change the years only when we actually modify those files (not sure if make tidy checks that).

[panzarino]

Sorry, I didn't know.

LICENSE-MIT and COPYRIGHT files should still be changed

I can update this PR to only change those files if that's what you would like.

[hanna-kruppe]

@eddyb We don't even consistently update the years when modifying files. As one random example, src/libsyntax/attr.rs has been modified throughout 2015 but is still "Copyright 2012-2014".

[frewsxcv]

These shouldn't be updated for the sake of being updated

Previous discussion: #9070

[eddyb]

@zachpanz88 If you want to work on this you could add support to src/etc/licenseck.py/src/etc/tidy.py to check the year based on the date of the git last commit.

I would be glad to have these updated according to their changes.

[panzarino]

I have updated this PR to only change the LICENSE-MIT and COPYRIGHT files.

@eddyb I can work on updating the files you mentioned above. You would want it to automatically update the comment at the top of the file to match the date at which the file was last updated correct?

[eddyb]

@zachpanz88 The scripts are supposed to check but not actually modify files. Auto-modification functionality would have to be separate.

[panzarino]

@eddyb Okay, so you want the program to check if the copyright date is the same as the last modified date and if not, display a message to the user.

[retep998]

Specifically those programs should cause make tidy to fail if they don't match, that way people would be forced to not forget.

[frewsxcv]

This pull request looks good to me with the latest changes

[nrc]

@bors: r+ rollup

[bors]

📌 Commit d5c8f62 has been approved by nrc

[bors]

⌛ Testing commit d5c8f62 with merge ebc6ca8...

[bors]

💔 Test failed - auto-linux-64-nopt-t

[panzarino]

Not sure how that could have happened

[eddyb]

@zachpanz88 It's spurious, we've seen a lot of these lately.

@bors retry

[bors]

⌛ Testing commit d5c8f62 with merge bd58fd8...

[bors]

☀️ Test successful - auto-linux-32-nopt-t, auto-linux-32-opt, auto-linux-64-debug-opt, auto-linux-64-nopt-t, auto-linux-64-opt, auto-linux-64-x-android-t, auto-linux-cross-opt, auto-linux-musl-64-opt, auto-mac-32-opt, auto-mac-64-nopt-t, auto-mac-64-opt, auto-win-gnu-32-nopt-t, auto-win-gnu-32-opt, auto-win-gnu-64-nopt-t, auto-win-gnu-64-opt, auto-win-msvc-32-opt, auto-win-msvc-64-opt