[Bug c++/88501] Improve suggested alternative to be closer to typo

[jg at jguk dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88501

--- Comment #5 from Jonny Grant <jg at jguk dot org> ---
(In reply to Jonathan Wakely from comment #4)
[..]
> > "st!ing"
> 
> ! is a single byte in UTF-8

Fair enough.  Just my idea below.

How about converting those two utf8 bytes, to a marker one byte, to help the
suggestion at least?  (although it still needs to get past the identifier
parser stopping at "st"

if(utf8_found)
{
    convert_utf8_to_to_char(inbuf, outbuf);
    suggest_alternative(outbuf);
}
else
{
    suggest_alternative(inbuf);
}

in this case, inbuf would contain "st£ing" and be 7bytes+NUL  and outbuf would
contain "str!ing" 6 bytes+NUL, that way, when it was compared, it would
correctly propose an identifier that was also 6 characters long