ast: Standardize visiting order

[petrochenkov]

Order: ID, attributes, inner nodes in source order if possible, tokens, span.

Also always use exhaustive matching in visiting infra, and visit some discovered missing nodes.

Unlike #125741 this shouldn't affect anything serious like macro_rules scopes.

[rustbot]

r? @BoxyUwU

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[rustbot]

Changes to the size of AST and/or HIR nodes.

cc @nnethercote

[nnethercote]

PathSegment hasn't changed in size. Something about the visitor must have changed, but I can't see what. Do you know?

[nnethercote]

This comment is relevant, it describes how the AST node measurements aren't perfect:

rust/compiler/rustc_passes/src/hir_stats.rs

Lines 47 to 63 in 4bc39f0

	/// This type measures the size of AST and HIR nodes, by implementing the AST
	/// and HIR `Visitor` traits. But we don't measure every visited type because
	/// that could cause double counting.
	///
	/// For example, `ast::Visitor` has `visit_ident`, but `Ident`s are always
	/// stored inline within other AST nodes, so we don't implement `visit_ident`
	/// here. In contrast, we do implement `visit_expr` because `ast::Expr` is
	/// always stored as `P<ast::Expr>`, and every such expression should be
	/// measured separately.
	///
	/// In general, a `visit_foo` method should be implemented here if the
	/// corresponding `Foo` type is always stored on its own, e.g.: `P<Foo>`,
	/// `Box<Foo>`, `Vec<Foo>`, `Box<[Foo]>`.
	///
	/// There are some types in the AST and HIR tree that the visitors do not have
	/// a `visit_*` method for, and so we cannot measure these, which is
	/// unfortunate.

[petrochenkov]

Paths in attributes are now visited.

[BoxyUwU]

@bors r+ rollup=never

cool :) visitor boilerplate is always kinda sketch when it just uses field accesses instead of exhaustively destructuring

[bors]

📌 Commit ba3f681 has been approved by BoxyUwU

It is now in the queue for this repository.

[bors]

⌛ Testing commit ba3f681 with merge 036b38c...

[bors]

☀️ Test successful - checks-actions
Approved by: BoxyUwU
Pushing 036b38c to master...

[rust-timer]

Finished benchmarking commit (036b38c): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.3%	[-1.3%, -1.3%]	1
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

This benchmark run did not return any relevant results for this metric.

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 696.635s -> 697.296s (0.09%)
Artifact size: 326.80 MiB -> 326.82 MiB (0.01%)