Use bound types in librustc_traits

[scalexm]

r? @nikomatsakis
see the tests which now move the higher-ranked binders to the left in implied bound rules!

[rust-highfive]

The job x86_64-gnu-llvm-5.0 of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

travis_time:end:15f77c2e:start=1541261676620823550,finish=1541261678798888953,duration=2178065403
$ git checkout -qf FETCH_HEAD
travis_fold:end:git.checkout

Encrypted environment variables have been removed for security reasons.
See https://docs.travis-ci.com/user/pull-requests/#Pull-Requests-and-Security-Restrictions
$ export SCCACHE_BUCKET=rust-lang-ci-sccache2
$ export SCCACHE_REGION=us-west-1
Setting environment variables from .travis.yml
$ export IMAGE=x86_64-gnu-llvm-5.0
---
[00:53:10] .................................................................................................... 4400/4984
[00:53:13] .................................................................................................... 4500/4984
[00:53:17] .......................................................i............................................ 4600/4984
[00:53:21] .................................................................................................... 4700/4984
user-annotations/dump-fn-method.rs" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/nll/user-annotations/dump-fn-method/a" "-Crpath" "-O" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-Zverbose" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/nll/user-annotations/dump-fn-method/auxiliary" "-A" "unused"
[00:53:28] ------------------------------------------
[00:53:28] 
[00:53:28] ------------------------------------------
[00:53:28] stderr:
[00:53:28] stderr:
[00:53:28] ------------------------------------------
[00:53:28] {"message":"user substs: Canonical { max_universe: U0, variables: [], value: UserSubsts { substs: [u32], user_self_ty: None } }","code":null,"level":"error","spans":[{"file_name":"/checkout/src/test/ui/nll/user-annotations/dump-fn-method.rs","byte_start":975,"byte_end":985,"line_start":36,"line_end":36,"column_start":13,"column_end":23,"is_primary":true,"text":[{"text":"    let x = foo::<u32>; //~ ERROR [u32]","highlight_start":13,"highlight_end":23}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[],"rendered":"error: user substs: Canonical { max_universe: U0, variables: [], value: UserSubsts { substs: [u32], user_self_ty: None } }\n  --> /checkout/src/test/ui/nll/user-annotations/dump-fn-method.rs:36:13\n   |\nLL |     let x = foo::<u32>; //~ ERROR [u32]\n   |             ^^^^^^^^^^\n\n"}
[00:53:28] {"message":"user substs: Canonical { max_universe: U0, variables: [Canon

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[bors]

☔ The latest upstream changes (presumably #55859) made this pull request unmergeable. Please resolve the merge conflicts.

[nikomatsakis]

It'd be nice to have a comment here.

---

Returns a substitution vector containing "identity references" suitable for converting from the compiler's parameter representation to the bound type representation used in Chalk. The Nth parameter is substituted to a bound variable of index N, pointing at the innermost binder.

[nikomatsakis]

I see you added this later :)

[nikomatsakis]

@bors r+

[bors]

📌 Commit 40208abdaae08e7c3ab89a167f086039ca9f6285 has been approved by nikomatsakis

[bors]

🔒 Merge conflict

This pull request and the master branch diverged in a way that cannot be automatically merged. Please rebase on top of the latest master branch, and let the reviewer approve again.

How do I rebase?

Assuming self is your fork and upstream is this repository, you can resolve the conflict following these steps:

1. git checkout chalk-bound-ty (switch to your branch)
2. git fetch upstream master (retrieve the latest master)
3. git rebase upstream/master -p (rebase on top of it)
4. Follow the on-screen instruction to resolve conflicts (check git status if you got lost).
5. git push self chalk-bound-ty --force-with-lease (update this PR)

You may also read Git Rebasing to Resolve Conflicts by Drew Blessing for a short tutorial.

Please avoid the "Resolve conflicts" button on GitHub. It uses git merge instead of git rebase which makes the PR commit history more difficult to read.

Sometimes step 4 will complete without asking for resolution. This is usually due to difference between how Cargo.lock conflict is handled during merge and rebase. This is normal, and you should still perform step 5 to update this PR.

Error message

warning: Cannot merge binary files: src/Cargo.lock (HEAD vs. heads/homu-tmp)
Auto-merging src/librustdoc/clean/mod.rs
Auto-merging src/librustc_typeck/collect.rs
Auto-merging src/librustc_typeck/check/mod.rs
Auto-merging src/librustc_traits/chalk_context/mod.rs
Auto-merging src/librustc_mir/borrow_check/nll/type_check/mod.rs
Auto-merging src/Cargo.lock
CONFLICT (content): Merge conflict in src/Cargo.lock
Automatic merge failed; fix conflicts and then commit the result.

[scalexm]

@bors r=nikomatsakis

[bors]

📌 Commit 8d0b969 has been approved by nikomatsakis

[bors]

⌛ Testing commit 8d0b969 with merge 5c9f7dc...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: nikomatsakis
Pushing 5c9f7dc to master...