Add bindgen::Builder::derive_copy

[mchlrhw]

Fixes #948

[fitzgen]

Thanks for the PR @mchlrhw ! The code looks great, but we need a test before we merge this.

Can you add something like this to tests/headers/do-not-derive-copy.hpp:

// bindgen-flags: --no-derive-copy

class WouldBeCopyButWeAreNotDerivingCopy {
    int x;
};

And then verify that the generated tests/expectations/tests/do-not-derive-copy.rs file doesn't add a derive(Copy).

Thanks again!

[mchlrhw]

Cool, thanks for pointing me in the right direction. I wasn't quite sure how testing worked, but your message and CONTRIBUTING.md really helped!

[fitzgen]

Cool, thanks for pointing me in the right direction. I wasn't quite sure how testing worked, but your message and CONTRIBUTING.md really helped!

Glad to hear that :)

[fitzgen]

@bors-servo r+

[bors-servo]

📌 Commit 537a49e has been approved by fitzgen

[bors-servo]

⌛ Testing commit 537a49e with merge 1e49750...

[bors-servo]

☀️ Test successful - status-travis
Approved by: fitzgen
Pushing 1e49750 to master...