[libcxx-commits] [libcxx] Reapply "[libc++] Optimize vector growing of trivially relocatable types" (PR #80558)

[David Blaikie via libcxx-commits]

dwblaikie wrote:

Agreed that they aren't allowed - but they have been (defacto, or intentionally - given the mention of the `allocator<const T>` extension) for some time. Removing them is probably good (though understanding why they were intentionally supported would probably be good to do before that) - but may need a longer migration plan so as not to break lots of code?

(might be worth reverting this patch to consider the fallout/whether there's a smoother way to stage this transition/removal?)

https://github.com/llvm/llvm-project/pull/80558