tree a74dd3184bcfda47c5681eddb1a8652578431393
parent a5c7da6696cf0148d8711215c08fc57ba114d41c
author Derek Mauro <dmauro@google.com> 1783614678 -0700
committer Copybara-Service <copybara-worker@google.com> 1783614773 -0700

Fix commit-before-construct bug in chunked_queue::emplace_back

* Modify AllocateBack() to only return raw storage without committing state (alloc_and_size_.size and tail_.ptr).
* Advance alloc_and_size_.size and tail_.ptr in emplace_back() only after AllocatorTraits::construct completes successfully.
* Add unit test ChunkedQueue.ExceptionSafetyEmplaceBack to verify exception safety.

PiperOrigin-RevId: 945160860
Change-Id: Ic5d628735ac7c3379b3f459f00694c53df74d5fa