## Summary
- Fix assertion failure when `Bun.indexOfLine` is called with a
non-number offset argument
- Changed from `.to(u32)` to `.coerce(i32, globalThis)` for proper
JavaScript type coercion
## Test plan
- [x] Added regression test in `test/js/bun/util/index-of-line.test.ts`
- [x] `bun bd test test/js/bun/util/index-of-line.test.ts` passes
Closes ENG-21997
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Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>