https://bugs.winehq.org/show_bug.cgi?id=48161
--- Comment #12 from Paul Gofman gofmanp@gmail.com --- I rechecked now, and the endbr instructions are not there in mingw built binaries in official built, those added flags don't go to CROSS_CFLAGS of course. Sorry I messed that up a bit as I was building everything explicitly with -fcf-protection when was reproducing the bug / locating some of "bad" dlls / functions.
So there is no problem with mingw / crossflags. I am just not entirely sure where that -fcf-protection flag listed in rpminfo comes from in official builds. If it is put to EXTRA_CFLAGS, then I suppose it should be ok now.