Rename splat to avoid stable name collisions

[teor2345]

Tracking issue: #153629

This PR renames #[splat] to #[rustc_splat], in a mostly automated way (using fastmod).

The rename commands I used were:

fastmod --fixed-strings '#[splat]' '#[rustc_splat]'
fastmod --fixed-strings '`splat` attribute' '`rustc_splat` attribute'
# I'm pretty sure the symbol demangling commands are no-ops on beta
# Legacy symbol demangling
fastmod --fixed-strings '$splat$' '$rustc_splat$'
# Revert some changes that aren't in rustc_demangle yet
fastmod 'v0(.*)#\[rustc_splat\]' 'v0${1}#[splat]' tests/ui/splat/splat-mangling.rs

Part of #159428

Backport Advice

Cherry-pick the first commit to the beta branch, then run the fastmod commands above.
I've tested this locally (with a slightly different name), and it works, see my splat-rename-beta branch.

Remaining Work

rustc_demangle needs an update to the attribute name, a release, and then a version bump in rust-lang/rust. I'll do that separately. It doesn't need to be backported, because the last version bump was after beta branched.

There's also some external code that needs updates, the full list is in the ticket: #159428 (comment)

@rustbot label +beta-nominated +A-attributes +A-macros +A-resolve +C-bug +F-splat +P-high +T-compiler

[rustbot]

The reflection data structures are tied exactly to the implementation
in the compiler. Make sure to also adjust rustc_const_eval/src/const_eval/type_info.rs

cc @oli-obk

This PR changes rustc_public

cc @oli-obk, @celinval, @ouz-a, @makai410

Some changes occurred in compiler/rustc_hir/src/attrs

cc @jdonszelmann, @JonathanBrouwer

rustfmt is developed in its own repository. If possible, consider making this change to rust-lang/rustfmt instead.

cc @rust-lang/rustfmt

Some changes occurred in compiler/rustc_attr_parsing

cc @jdonszelmann, @JonathanBrouwer

[teor2345]

No P-high for me!

@rustbot label +beta-nominated +A-attributes +A-macros +A-resolve +C-bug +F-splat +T-compiler

[jieyouxu]

FWIW we only assign P-* for issues not PRs; I'm happy to review the rename.
r? me

[apiraino]

I will "de-nominate" from backport as now it's a bit too early. Feel free to nominate again when the PR is reviewed and approved :)

@rustbot label -beta-nominated

[ytmimi]

Please restore src/tools/rustfmt/tests/source/reorder_modules/ZYXW/mod.rs, src/tools/rustfmt/tests/source/reorder_modules/ZYXW/mod.rs, src/tools/rustfmt/tests/target/reorder_modules/ABCD/mod.rs, src/tools/rustfmt/tests/target/reorder_modules/ZYXW/mod.rs

Removing these files is causing rustfmt test failures:

  thread '<unnamed>' (54612) panicked at src/tools/rustfmt/src/test/mod.rs:842:40:
  called `Result::unwrap()` on an `Err` value: ModuleResolutionError(ModuleResolutionError { module: "ZYXW", kind: NotFound { file: "tests/target/reorder_modules/ZYXW.rs" }

View changes since this review

[rustbot]

Reminder, once the PR becomes ready for a review, use @rustbot ready.

[teor2345]

This should be ready for review again.

The search and replace is less complicated, but making the attribute longer means there's some long lines to reformat or tidy up. Most of these are in tests that aren't in the beta branch.

@rustbot ready

[teor2345]

Pretty sure that was #160049, I'll rebase tomorrow. This PR is likely to be bitrotty, because there's a lot of search and replace.

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.