http://bugs.winehq.org/show_bug.cgi?id=25273
--- Comment #2 from Jörg Höhle hoehle@users.sourceforge.net 2010-11-30 07:05:18 CST --- http://gcc.gnu.org/ml/gcc-help/2006-10/msg00138.html explains that although sizeof() may be 16 or 12, the actual payload is 10 Bytes! (80 bit float format).
Surprisingly, FreeBSD machines pass the msvcrt/misc test. They should not, according to the above message (*BSD equating double with long double) -- perhaps sizeof(long double) is 12 even though only 64 bits are used on FreeBSD?