Am 13.11.2020 um 03:45 schrieb Alex Henrie <alexhenrie24@gmail.com>:

However, if MinGW is not installed, Wine's build system will compile
that same source code with L-strings as an SO module and it works
thanks to the -fshort-wchar compiler flag. So what's stopping us from
using -fshort-wchar and L-strings everywhere?

A non-mingw compiled PE module will only call other Wine libraries and only use Wine headers, so -fshort-wchar is an option. A not-yet-split module like msvcrt.dll.so will include system headers and call unix libraries so we can't safely use -fshort-wchar.