[Bug libstdc++/85824] regex constructor crashes under UTF-8 locale on Solaris SPARC when parsing a simple character class

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85824

--- Comment #9 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #8)
> We should also consider only caching chars in the range 0-127, because
> otherwise as this bug shows we call transform_primary for 128 char values
> which always fail.

Which I suppose is similar to Tim's enum { MATCHED, NOT_MATCHED, NOT_CACHED }
suggestion, but without storing an enum and just treating everything above 127
as not cached.