Align to recent pcase changes on Emacs master

[manuel-uberti]

This PR aims to support the recent changes on pcase introduced on Emacs master while keeping backward compatibility.

See #584
And this thread on emacs-devel for the solution proposed by Stefan Monnier

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Thanks!

[manuel-uberti]

@bbatsov Sorry about the CircleCI failures, am I missing something?

[manuel-uberti]

FWIW, I ran make test and got Ran 264 specs, 0 failed, in 5.54s.

[bbatsov]

@bbatsov Sorry about the CircleCI failures, am I missing something?

Likely something was changed in the images we're using.

[manuel-uberti]

Likely something was changed in the images we're using.

I see. Do you need me to do something else on this PR, then? I mean code-wise, because I wouldn't know how to help with CircleCI. :)

[bbatsov]

I fixed the CI images, so you can push something to your branch and see if the CI passes now.

[manuel-uberti]

Done, thank you!

[bbatsov]

Thanks!