[llvm] Introduce paged vector (PR #66430)

[Chuanqi Xu via llvm-commits]

https://github.com/ChuanqiXu9 commented:

Thanks. Sorry for not commenting everything at the first sight. I don't have further concerns. But I'd like to give more times for other reviewers to take a look.

https://github.com/llvm/llvm-project/pull/66430