https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67096
--- Comment #4 from John Marino <gnugcc at marino dot st> --- Created attachment 36332 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36332&action=edit codecvt/max_length/wchar/4.cc patch codecvt/max_length/wchar/4.cc test thinks that 6 is the maximum byte size for UTF-8 and fails if it detects lengths less than 6 bytes. Of course, the true limit is 4 bytes, so the test needs to be changed from 6 to 4. It is related to the tests this PR fixed (same problem, different form).
