resolve: Split macro prelude into built-in and user-defined parts

[petrochenkov]

This is a refactoring that will help to remove unshadowable_attrs when #53410 lands.

UPDATE: The second commit actually removes unshadowable_attrs.

[rust-highfive]

r? @eddyb

(rust_highfive has picked a reviewer for you, use r? to override)

[petrochenkov]

r? @alexcrichton

[alexcrichton]

@bors: r+

[bors]

📌 Commit 01a255a6442d821785c0ccf8fc8a3bfb95f445d4 has been approved by alexcrichton

[bors]

☔ The latest upstream changes (presumably #53410) made this pull request unmergeable. Please resolve the merge conflicts.

[petrochenkov]

Updated with a second commit removing unshadowable_attrs.

[petrochenkov]

@bors r=alexcrichton p=1
I'm going to r+ based on review of the first commit, otherwise we'll have too much code to backport after beta (which is in a few days).

[bors]

📌 Commit 4e97cd26732bb8191eaa876312d6ca1e2a8e401a has been approved by alexcrichton

[bors]

💡 This pull request was already approved, no need to approve it again.

• There's another pull request that is currently being tested, blocking this pull request: rustc_resolve: inject uniform_paths canaries regardless of the feature-gate, on Rust 2018. #54011

[bors]

📌 Commit 4e97cd26732bb8191eaa876312d6ca1e2a8e401a has been approved by alexcrichton

[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 2macpre (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 2macpre --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: inexact rename detection was skipped due to too many files.
warning: you may want to set your merge.renamelimit variable to at least 2774 and retry the command.
Auto-merging src/librustc_resolve/macros.rs
CONFLICT (content): Merge conflict in src/librustc_resolve/macros.rs
Auto-merging src/librustc_resolve/lib.rs
CONFLICT (content): Merge conflict in src/librustc_resolve/lib.rs
Auto-merging src/librustc_resolve/build_reduced_graph.rs
Automatic merge failed; fix conflicts and then commit the result.

[bors]

☔ The latest upstream changes (presumably #53778) made this pull request unmergeable. Please resolve the merge conflicts.

[petrochenkov]

@bors r=alexcrichton

[bors]

📌 Commit 62c7d78 has been approved by alexcrichton

[bors]

⌛ Testing commit 62c7d78 with merge fdcd4a4...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: alexcrichton
Pushing fdcd4a4 to master...