[Bug libstdc++/66359] Regex Fails to match

[georg@schorsch-tech.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66359

--- Comment #4 from georg@schorsch-tech.de ---
Created attachment 35666
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35666&action=edit
tried backport of 217461