Derive PartialEq Analysis

[photoszzt]

Fix: #878 r? @fitzgen

[bors-servo]

☔ The latest upstream changes (presumably #906) made this pull request unmergeable. Please resolve the merge conflicts.

[fitzgen]

@bors-servo r+

Thanks @photoszzt, looks perfect :)

We should figure out a way to DRY up all of these derive-related analysis, but I need to think about how to change our abstractions to be more precise about this stuff some more.

[bors-servo]

📌 Commit dc2baed has been approved by fitzgen

[bors-servo]

⌛ Testing commit dc2baed with merge 7e84c43...

[photoszzt]

@fitzgen the CanDeriveTrivially{Debug, Copy...} are also very redundant.

I notice that the stable rust is still generating the BindgenUnion with Copy field. Next step would be enable those in stable. I'm not sure which version of Rust has stable union. 19? Or something previous?

[bors-servo]

☀️ Test successful - status-travis
Approved by: fitzgen
Pushing 7e84c43 to master...

[fitzgen]

I notice that the stable rust is still generating the BindgenUnion with Copy field. Next step would be enable those in stable. I'm not sure which version of Rust has stable union. 19? Or something previous?

You can do rustup update stable to get the latest stable rustc toolchain, and then rustc --version.

I thought we should be generating unions after @tmfink's PR that just landed. It looks like it is to me. All the _1_0.rs files targetting older stable rust use BindgenUnion and all the others targeting the latest stable release are using union.