[Bug preprocessor/94127] #pragma system_header marks unrelated files as system headers

[aleksey.covacevice at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94127

--- Comment #2 from Aleksey Covacevice <aleksey.covacevice at gmail dot com> ---
(In reply to Jonathan Wakely from comment #1)
> I think it's intended.
> 
> You should put the pragma after including other headers if you don't want
> them to be affected.

What does the pragma have to do with *any* of the other include files,
specially considering that `usr.h` has been included from the main source file
in the example?