Derive PartialOrd when possible

[pepyakin]

Fixes #882

r? @fitzgen

[fitzgen]

This looks good!

We just need some test coverage to land this. Let's add --with-derive-partialord to the // bindgen-flags line for these tests:

• tests/headers/derive-hash-template-inst-float.hpp
• tests/headers/derive-hash-template-def-float.hpp
• tests/headers/derive-hash-struct-with-pointer.h
• tests/headers/derive-hash-struct-with-float-array.h
• tests/headers/derive-hash-struct-with-anon-struct-float.h
• tests/headers/derive-hash-blacklisting.hpp

And then verify that the generated bindings do or don't derive(PartialOrd) as we expect them to.

Thanks!

[fitzgen]

@pepyakin, BTW, I'm not sure if you're aware that the "impl period" has just begun, but the folks hacking on bindgen during the impl period are hanging out in https://gitter.im/rust-impl-period/WG-dev-tools-bindgen if you want to join us :)

[fitzgen]

@bors-servo r+

Thanks @pepyakin !

[bors-servo]

📌 Commit e4a4b47 has been approved by fitzgen

[bors-servo]

⌛ Testing commit e4a4b47 with merge 1906a26...

[bors-servo]

☀️ Test successful - status-travis
Approved by: fitzgen
Pushing 1906a26 to master...

[bors-servo]

☀️ Test successful - status-travis
Approved by: fitzgen
Pushing 1906a26 to master...