[clang] Reapply "[Clang][CWG1815] Support lifetime extension of temporary created by aggregate initialization using a default member initializer" (PR #92527)

[via cfe-commits]

bgra8 wrote:

heads-up @yronglin: we've bisected many compilation breakages to this patch.
We're working on a reproducer.

https://github.com/llvm/llvm-project/pull/92527