refactor(parser): make Modifier Copy

[overlookmotel]

#20823 reduced Modifier to 8 bytes. So it's now pointless passing around &Modifiers (also 8 bytes).

Make Modifier Copy and pass around owned Modifiers instead.

[overlookmotel]

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• refactor(parser): Modifiers::add take Modifier as param #20825
• refactor(parser): make Modifier Copy #20824 👈 (View in Graphite)
• perf(parser): defer calculation of Modifier spans #20823 : 1 other dependent PR (#20826 )
• perf(parser): remove branch from parse_modifiers #20821
• perf(parser): reduce Kind to ModifierKind conversions in eat_modifiers_before_declaration #20820
• 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

Refactors the parser’s Modifier value type to be trivially copyable now that it’s only 8 bytes, reducing unnecessary &Modifier passing and simplifying call sites in modifier validation and diagnostics paths.

Changes:

• Derive Copy for Modifier and change Modifier::span to take self by value.
• Update parser modifier-checking helpers and verify_modifiers callback signatures to accept Modifier by value.
• Adjust diagnostics call sites to pass owned Modifier values instead of references.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
crates/oxc_parser/src/modifiers.rs	Makes Modifier Copy, updates span receiver and internal modifier validation APIs to take modifiers by value.
crates/oxc_parser/src/js/module.rs	Updates a diagnostics call site to pass an owned Modifier instead of &Modifier.
crates/oxc_parser/src/diagnostics.rs	Changes modifier-related diagnostic constructors to accept Modifier by value to match the new value semantics.

[codspeed-hq]

Merging this PR will not alter performance

✅ 48 untouched benchmarks
⏩ 8 skipped benchmarks¹

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_{Comparing om/03-28-refactor_parser_make_modifier_copy_ (bbef4f3) with om/03-28-perf_parser_defer_calculation_of_modifier_spans (e6c5fb8)}

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. ↩

[overlookmotel]

Codspeed says (surprisingly) that this is a small perf regression. So closing.