http://bugs.winehq.org/show_bug.cgi?id=28050
--- Comment #3 from Duncan Sands baldrick@free.fr 2011-08-11 08:26:59 CDT --- Well, loader/preloader.c isn't compiled with -fno-builtins (wine version 1.27). Thus it is OK for the compiler to synthesize a call to memset in it. So if wine requires that there be no such calls, then it is a wine bug that -fno-builtins was not used.
Of course, -fno-builtins won't help until dragonegg is fixed to pay attention to it.