toolchain/58000: llvm: Freezing C++03 headers in libc++

[campbell+netbsd%mumble.net@localhost]

>Number:         58000
>Category:       toolchain
>Synopsis:       llvm: Freezing C++03 headers in libc++
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    toolchain-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Mar 06 01:00:00 +0000 2024
>Originator:     Taylor R Campbell
>Release:        
>Organization:
The NetBSD Clangdation
>Environment:
>Description:
Something is happening with libc++ header files upstream:

https://discourse.llvm.org/t/rfc-freezing-c-03-headers-in-libc/77319

May require changes on our part or input from us to upstream, not sure, didn't read the whole post.
>How-To-Repeat:

>Fix:
Maybe?