UNRELEASED.md
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### Internal
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### Performance
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### Performance
- Optimize `Hash#rehash` for the common case, avoid calling `$slice` when no hash collision is present (#2571)
### Fixed
- `String#{r,l,}strip`: Make them work like in MRI for non-breaking white-space (#2612)
- Compat regression fix: `Hash#to_n` should return a JS object (#2613)
### Internal
- Bump the ECMA version from 3 to 12 for ESLint (#2537)