fix(formatter): Honor trailing ignore comments after list separators

[alubbe]

Summary

After running the new oxfmt release (which comes with #19304) against our code base, we found one case where trailing ignore comments aren't properly interpreted (playground link at the end of this PR).

const items = [
  {a:aa(),b:bb(),c:cc(),d:dd(),e:ee(),f:ff(),g:gg()}, // prettier-ignore
];

Prettier keeps the code as-is, but oxfmt turns it into:

const items = [
  { a: aa(), b: bb(), c: cc(), d: dd(), e: ee(), f: ff(), g: gg() }, // prettier-ignore
];

Root cause

• Trailing suppression detection only allowed whitespace/=/: between node end and comment.
• In list items, there is typically a comma before the trailing comment (}, // prettier-ignore).
• Expression formatting path also needed trailing suppression handling.

Changes

• Extended trailing suppression gap handling to include list separators (',', ';').
• Reused a shared internal comment scan helper to avoid duplicated logic between:
  • end-of-line comment detection
  • trailing suppression detection
• Added trailing suppression handling for AstNode<Expression>.
• Updated the formatter generator accordingly so regenerated code keeps this behavior.

Validation

Ran:

• cargo test -p oxc_formatter --test mod fixtures::js::ignore
• cargo test -p oxc_formatter --test mod fixtures::ts::ignore

Both pass.

AI disclosure

This PR was prepared with AI assistance (Codex), and all changes were reviewed and validated by the author.

https://playground.oxc.rs/?t=formatter&options=%7B%22run%22%3A%7B%22lint%22%3Atrue%2C%22formatter%22%3Atrue%2C%22transform%22%3Afalse%2C%22isolatedDeclarations%22%3Afalse%2C%22whitespace%22%3Afalse%2C%22mangle%22%3Afalse%2C%22compress%22%3Afalse%2C%22scope%22%3Atrue%2C%22symbol%22%3Atrue%2C%22cfg%22%3Afalse%7D%2C%22parser%22%3A%7B%22extension%22%3A%22tsx%22%2C%22allowReturnOutsideFunction%22%3Atrue%2C%22preserveParens%22%3Atrue%2C%22allowV8Intrinsics%22%3Atrue%2C%22semanticErrors%22%3Atrue%7D%2C%22linter%22%3A%7B%7D%2C%22formatter%22%3A%7B%22useTabs%22%3Afalse%2C%22tabWidth%22%3A2%2C%22endOfLine%22%3A%22lf%22%2C%22printWidth%22%3A80%2C%22singleQuote%22%3Afalse%2C%22jsxSingleQuote%22%3Afalse%2C%22quoteProps%22%3A%22as-needed%22%2C%22trailingComma%22%3A%22all%22%2C%22semi%22%3Atrue%2C%22arrowParens%22%3A%22always%22%2C%22bracketSpacing%22%3Atrue%2C%22bracketSameLine%22%3Afalse%2C%22objectWrap%22%3A%22preserve%22%2C%22singleAttributePerLine%22%3Afalse%7D%2C%22transformer%22%3A%7B%22target%22%3A%22es2015%22%2C%22useDefineForClassFields%22%3Atrue%2C%22experimentalDecorators%22%3Atrue%2C%22emitDecoratorMetadata%22%3Atrue%7D%2C%22isolatedDeclarations%22%3A%7B%22stripInternal%22%3Afalse%7D%2C%22codegen%22%3A%7B%22normal%22%3Atrue%2C%22jsdoc%22%3Atrue%2C%22annotation%22%3Atrue%2C%22legal%22%3Atrue%7D%2C%22compress%22%3A%7B%7D%2C%22mangle%22%3A%7B%22topLevel%22%3Atrue%2C%22keepNames%22%3Afalse%7D%2C%22controlFlow%22%3A%7B%22verbose%22%3Afalse%7D%2C%22inject%22%3A%7B%22inject%22%3A%7B%7D%7D%2C%22define%22%3A%7B%22define%22%3A%7B%7D%7D%7D&code=const+items+%3D+%5B%0A++%7Ba%3Aaa%28%29%2Cb%3Abb%28%29%2Cc%3Acc%28%29%2Cd%3Add%28%29%2Ce%3Aee%28%29%2Cf%3Aff%28%29%2Cg%3Agg%28%29%7D%2C+%2F%2F+prettier-ignore%0A%5D%3B%0A

[codspeed-hq]

Merging this PR will not alter performance

✅ 49 untouched benchmarks
⏩ 7 skipped benchmarks¹

---

_{Comparing alubbe:trailing-comment-array-of-objects (641051e) with main (a607119)}

Footnotes

1. 7 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. ↩