[Bug c++/90468] Documentation: typo in the part that tells whether the positive or the negative form of an option is documented

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90468

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Would "efficacy of warnings about control- and data-flow" with an extra hyphen
be better?