refactor(rome_js_formatter): avoid snapshot when formatting skipped token trivia

[MichaReiser]

Summary

This removes the need to take a snapshot before formatting leading trivia by collecting the comments into a Vec. The performance characteristics of the new implementation should be similar to the old because it removes the need to allocate a temporary VecBuffer to be able to reverse the written comments in the end.

I find this solution slightly easier to reason about and results in slightly less code:

Before:

• 3.5% 10.9% 422.4KiB rome_js_formatter
• 0.1% 0.4% 9.7KiB rome_js_formatter <rome_js_formatter::builders::FormatLeadingTrivia as rome_formatter::Format<rome_js_formatter::context::JsFormatContext>>::fmt

After:

• 3.3% 10.6% 407.1KiB rome_js_formatter
• FormatLeadingTrivia no longer shows up.

It also gives us the option to use a SmallVec to store comments if profiling shows that this is beneficial.

Test Plan

cargo test

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[github-actions]

Playground for commit 28fc0f2

[github-actions]

Parser conformance results on ubuntu-latest

js/262

Test result	main count	This PR count	Difference
Total	45878	45878	0
Passed	44938	44938	0
Failed	940	940	0
Panics	0	0	0
Coverage	97.95%	97.95%	0.00%

jsx/babel

Test result	main count	This PR count	Difference
Total	39	39	0
Passed	36	36	0
Failed	3	3	0
Panics	0	0	0
Coverage	92.31%	92.31%	0.00%

symbols/microsoft

Test result	main count	This PR count	Difference
Total	5946	5946	0
Passed	350	350	0
Failed	5595	5595	0
Panics	1	1	0
Coverage	5.89%	5.89%	0.00%

ts/babel

Test result	main count	This PR count	Difference
Total	588	588	0
Passed	519	519	0
Failed	69	69	0
Panics	0	0	0
Coverage	88.27%	88.27%	0.00%

ts/microsoft

Test result	main count	This PR count	Difference
Total	16257	16257	0
Passed	12391	12391	0
Failed	3866	3866	0
Panics	0	0	0
Coverage	76.22%	76.22%	0.00%

[MichaReiser]

!bench_formatter

[github-actions]

Formatter Benchmark Results

group                                    main                                   pr
-----                                    ----                                   --
formatter/checker.ts                     1.00   361.4±14.45ms     7.2 MB/sec    1.02   368.9±19.69ms     7.0 MB/sec
formatter/compiler.js                    1.00   211.4±11.69ms     5.0 MB/sec    1.02    215.4±7.66ms     4.9 MB/sec
formatter/d3.min.js                      1.00    157.7±8.01ms  1701.5 KB/sec    1.09    171.3±7.76ms  1567.2 KB/sec
formatter/dojo.js                        1.00     11.1±0.60ms     6.2 MB/sec    1.00     11.2±0.40ms     6.2 MB/sec
formatter/ios.d.ts                       1.08    258.2±9.15ms     7.2 MB/sec    1.00   238.2±11.19ms     7.8 MB/sec
formatter/jquery.min.js                  1.00     48.9±2.95ms  1730.6 KB/sec    1.05     51.4±3.35ms  1647.2 KB/sec
formatter/math.js                        1.01   372.4±13.95ms  1780.8 KB/sec    1.00   367.7±16.99ms  1803.1 KB/sec
formatter/parser.ts                      1.06      7.7±0.27ms     6.3 MB/sec    1.00      7.2±0.26ms     6.7 MB/sec
formatter/pixi.min.js                    1.00    181.3±9.61ms     2.4 MB/sec    1.05    190.8±6.34ms     2.3 MB/sec
formatter/react-dom.production.min.js    1.00     50.9±2.42ms     2.3 MB/sec    1.04     53.1±2.32ms     2.2 MB/sec
formatter/react.production.min.js        1.14      3.0±0.28ms     2.0 MB/sec    1.00      2.7±0.12ms     2.3 MB/sec
formatter/router.ts                      1.09      6.3±0.29ms     9.7 MB/sec    1.00      5.8±0.29ms    10.6 MB/sec
formatter/tex-chtml-full.js              1.04   494.5±22.05ms  1887.1 KB/sec    1.00   475.2±12.96ms  1963.9 KB/sec
formatter/three.min.js                   1.06    228.4±9.71ms     2.6 MB/sec    1.00    214.9±7.21ms     2.7 MB/sec
formatter/typescript.js                  1.03  1373.3±63.45ms     6.9 MB/sec    1.00  1339.1±48.85ms     7.1 MB/sec
formatter/vue.global.prod.js             1.07     77.5±2.21ms  1592.0 KB/sec    1.00     72.1±3.44ms  1710.7 KB/sec