[Bug target/107878] Incomplete documentation for H8/300

[jdx at o2 dot pl]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107878

--- Comment #2 from Jan Dubiec <jdx at o2 dot pl> ---
One more thing – the documentation on the webpage states that -mn "must be used
either with -mh or -ms". It is true for old compilers (e.g. for gcc 4.7 which I
still use) but does not seem to be true for new ones, i.e. it is possible pass
-mn alone at least to gcc 12.2. BTW. As far as I can see support for H8/300
(pure 16-bit MCUs, do not confuse with H8/300H) has been (justifiably) removed
since mid-2020 – IMO it is worth to mention about that fact in the
documentation.