fix(linter): avoid false positive for 3e-308

[Boshen]

Summary

• fix eslint/no-loss-of-precision false positive for 3e-308 by simplifying internal precision formatting
• align test coverage with ESLint's current no-loss-of-precision test cases (including TS cases)
• keep additional Oxc regression coverage for subnormal/underflow literals

Closes #19988

Testing

• cargo test -p oxc_linter no_loss_of_precision -- --nocapture

AI usage disclosure

This PR was prepared with AI assistance, and I reviewed and validated the generated changes and test updates.

[Copilot]

Pull request overview

Fixes eslint/no-loss-of-precision false positives for very small literals (e.g. 3e-308) by simplifying internal precision-string generation, and updates snapshots/tests to align with ESLint’s current test cases (including TS/TSX coverage).

Changes:

• Replace the custom toPrecision-like formatting logic with Rust scientific formatting to avoid truncation for very small exponents.
• Expand pass/fail test vectors to include additional exponent/TS cases and underflow/subnormal regressions.
• Update the rule snapshot output to reflect the new/expanded test coverage.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
crates/oxc_linter/src/rules/eslint/no_loss_of_precision.rs	Simplifies to_precision implementation and updates rule test cases for additional exponent/TS and underflow scenarios.
crates/oxc_linter/src/snapshots/eslint_no_loss_of_precision.snap	Updates expected diagnostics to match the expanded test coverage.

[codspeed-hq]

Merging this PR will not alter performance

✅ 4 untouched benchmarks
⏩ 52 skipped benchmarks¹

---

_{Comparing fix/no-loss-of-precision-3e-308 (7d1d07f) with main (6245c56)}

Footnotes

1. 52 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. ↩

[chatgpt-codex-connector]

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[Boshen]

Addressed review feedback in 7d1d07fa39:

• restored JS-style toPrecision formatting behavior in the rule path (fixes the reported rounding regression)
• fixed tiny-exponent handling by extracting digits from high-precision scientific notation (3e-308 case)
• added runtime precision guard with assert!((1..=100).contains(&precision)) and made to_precision private to the module
• aligned normalization with ESLint's raw-vs-stored behavior (parseAsFloat equivalent)
• added regression coverage for 39782723799.5411758422851563 in the original test vectors

Validation:

• cargo test -p oxc_linter no_loss_of_precision -- --nocapture
• manual check: 3e-308 and 39782723799.5411758422851563 are no longer flagged; 9007199254740993 is still flagged.