[libcxx-commits] [libcxx] [libc++] Include the rest of the detail headers by version in the umbrella headers (PR #96032)

[David Tenty via libcxx-commits]

daltenty wrote:

@philnik777 this PR has some strange side-effects, namely it put `<format>` (which is a C++20 header) in the transitive include set for language modes less that `C++20`. 

A few of our users report this has strange effects when using `C++17` with user headers named `format`. Is this change required?

https://github.com/llvm/llvm-project/pull/96032