perf(formatter): use VecDeque for member chain groups

[Boshen]

Summary

• Replace Vec with VecDeque for TailChainGroups storage
• pop_first() now uses pop_front() which is O(1) instead of O(n) remove(0)

Changes

Operation	Before	After
pop_first()	remove(0) - O(n) shift	pop_front() - O(1)
first()	first()	front()
last()	last()	back()
push	push()	push_back()

Impact

Improves performance when formatting long member chains like a.b().c().d().e() where the first group may be merged with the head.

Test plan

• cargo test -p oxc_formatter passes (144 tests)
• Prettier conformance unchanged (97.77% js, 96.37% ts)

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR optimizes the formatter's member chain handling by replacing Vec with VecDeque for storing tail chain groups. The change improves the performance of pop_first() operations from O(n) to O(1), which benefits formatting of long member chains.

Changes:

• Replaced Vec with VecDeque for TailChainGroups and MemberChainGroupsBuilder storage
• Updated all collection operations to use VecDeque-specific methods (push_back, pop_front, front, back)
• Refactored any_except_last_will_break() to use iterator-based approach compatible with VecDeque

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[codspeed-hq]

CodSpeed Performance Report

Merging this PR will not alter performance

_{Comparing perf/formatter-vecdeque-member-chain (eef381a) with main (618c629)}

Summary

✅ 38 untouched benchmarks
⏩ 7 skipped benchmarks¹

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. ↩

[Dunqing]

Merge activity

• Jan 19, 1:32 AM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Jan 19, 1:32 AM UTC: Dunqing added this pull request to the Graphite merge queue.
• Jan 19, 1:38 AM UTC: Merged by the Graphite merge queue.