[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:

I reverted this and the dependent patch based on https://github.com/llvm/llvm-project/pull/92527#issuecomment-2149120420 to bring back the repo back to green. 

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