perf(parser): reduce Kind to ModifierKind conversions in eat_modifiers_before_declaration

[overlookmotel]

Small perf optimization.

eat_modifiers_before_declaration was converting Kind to ModifierKind twice - once in self.at_modifier() (kind.is_modifier_kind()), and then again in self.modifier() (ModifierKind::try_from(kind)).

Instead, convert only once.

+0.1% improvement on most parser benchmarks.

[overlookmotel]

• perf(parser): defer calculation of Modifier spans #20823 : 2 dependent PRs (#20824 , #20826 )
• perf(parser): remove branch from parse_modifiers #20821
• perf(parser): reduce Kind to ModifierKind conversions in eat_modifiers_before_declaration #20820 👈 (View in Graphite)
• refactor(parser): shorten code handling illegal modifiers #20781
• perf(parser): fast path for no syntax errors when checking modifiers #20748
• perf(parser): remove a lookahead from eat_modifiers_before_declaration #20755
• refactor(parser): nest modifiers types in modules #20754
• refactor(parser): re-order modifiers code #20753
• perf(parser): store Modifiers on stack #20742
• perf(parser): add Modifiers::get method #20741
• refactor(parser): rename ModifierKinds::empty to none #20740
• refactor(parser): rename ModifierFlags to ModifierKinds #20739
• refactor(parser): simplify ModifierFlags #20738
• refactor(parser): import from std at top level #20737
• refactor(parser): remove Modifier::is_static() #20736
• refactor(parser): remove dead code from modifier parsing #20735
• main

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[Copilot]

Pull request overview

Optimizes oxc_parser modifier parsing by avoiding redundant Kind -> ModifierKind conversions in eat_modifiers_before_declaration, keeping the same lookahead-based correctness checks while reducing work on the hot path.

Changes:

• Replace at_modifier() + modifier() flow with a single get_modifier() that returns Option<ModifierKind>.
• Construct Modifier directly from the already-converted ModifierKind.
• Rename/update the lookahead worker accordingly.

[codspeed-hq]

Merging this PR will not alter performance

✅ 48 untouched benchmarks
⏩ 8 skipped benchmarks¹

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_{Comparing om/03-28-perf_parser_reduce_kind_to_modifierkind_conversions_in_eat_modifiers_before_declaration_ (eb02c88) with main (2529cfb)²}

Footnotes

1. 8 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. No successful run was found on main (eb02c88) during the generation of this report, so 2529cfb was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[camc314]

Merge activity

• Mar 29, 3:30 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Mar 29, 3:31 PM UTC: camc314 added this pull request to the Graphite merge queue.
• Mar 29, 3:35 PM UTC: The Graphite merge queue removed this pull request due to downstack failures on PR #20781.
• Mar 29, 3:35 PM UTC: The Graphite merge queue removed this pull request due to downstack failures on PR #20781.
• Mar 29, 3:36 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Mar 29, 3:36 PM UTC: The merge label '0-merge' was removed. This PR will no longer be merged by the Graphite merge queue
• Mar 29, 3:37 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Mar 29, 3:37 PM UTC: The merge label '0-merge' was removed. This PR will no longer be merged by the Graphite merge queue
• Mar 29, 3:38 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Mar 29, 3:40 PM UTC: camc314 added this pull request to the Graphite merge queue.
• Mar 29, 3:40 PM UTC: graphite-app removed this pull request from the Graphite merge queue.
• Mar 29, 3:40 PM UTC: The merge label '0-merge' was removed. This PR will no longer be merged by the Graphite merge queue
• Mar 29, 3:41 PM UTC: camc314 added this pull request to the Graphite merge queue.
• Mar 29, 4:20 PM UTC: This pull request was removed from the Graphite merge queue because the batch it was included in timed out. Please re-enqueue the PR to retry merge.
• Mar 29, 4:37 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Mar 29, 4:37 PM UTC: camc314 added this pull request to the Graphite merge queue.
• Mar 29, 4:37 PM UTC: Merged by the Graphite merge queue.