https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70722
--- Comment #13 from Jonathan Wakely <redi at gcc dot gnu.org> --- The C standard has equivalent wording in 7.1.2: If a file with the same name as one of the above < and > delimited sequences, not provided as part of the implementation, is placed in any of the standard places that are searched for included source files, the behavior is undefined.
