Remove token::Lit from ast::Lit.

[nnethercote]

token::Lit contains a kind field that indicates what kind of literal it is. ast::Lit currently wraps a token::Lit but also has its own kind field. Which means that ast::Lit encodes the literal kind in two different ways.

This commit changes ast::Lit so it no longer wraps token::Lit. It now contains the symbol and suffix fields from token::Lit, but not the kind field, eliminating the redundancy. This requires extending ast::LitKind::ByteStr to include a StrStyle to properly distinguish between cooked and raw byte string literals at the ast::Lit level.

r? @petrochenkov

[rustbot]

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

Some changes occurred in src/tools/rustfmt

cc @rust-lang/rustfmt

[nnethercote]

I'm not expecting much performance effect, but let's check anyway:

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

[bors]

⌛ Trying commit c16f710 with merge 1c91510426b7b23caa649d60e0f31de9e5b09678...

[bors]

☀️ Try build successful - checks-actions
Build commit: 1c91510426b7b23caa649d60e0f31de9e5b09678 (1c91510426b7b23caa649d60e0f31de9e5b09678)

[rust-timer]

Queued 1c91510426b7b23caa649d60e0f31de9e5b09678 with parent 0568b0a, future comparison URL.

[rust-timer]

Finished benchmarking commit (1c91510426b7b23caa649d60e0f31de9e5b09678): comparison URL.

Overall result: ❌✅ regressions and improvements - ACTION NEEDED

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.

@bors rollup=never
@rustbot label: +S-waiting-on-review -S-waiting-on-perf +perf-regression

Instruction count

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

	mean1	range	count2
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.0%	[2.0%, 2.0%]	1
Improvements ✅ (primary)	-0.8%	[-1.0%, -0.7%]	6
Improvements ✅ (secondary)	-1.9%	[-1.9%, -1.9%]	1
All ❌✅ (primary)	-0.8%	[-1.0%, -0.7%]	6

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean1	range	count2
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.1%	[2.1%, 2.1%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean1	range	count2
Regressions ❌ (primary)	2.2%	[2.2%, 2.2%]	1
Regressions ❌ (secondary)	3.4%	[2.5%, 4.8%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.4%	[-3.4%, -3.4%]	1
All ❌✅ (primary)	2.2%	[2.2%, 2.2%]	1

Footnotes

1. the arithmetic mean of the percent change↩↩²↩³

2. number of relevant changes↩↩²↩³

[nnethercote]

The html5ever improvements are probably noise, which means this is performance-neutral.

@rustbot label: +perf-regression-triaged

[nnethercote]

I have moved this into #101562, where it's one of several changes required to shrink ast::Expr.