Hojun-Cho
60c3e51dc5
Basic x98_nested_arg only spills the imported f64 call-result into the
first float slot (X0); a multi-f64-arg call forces the spill into X2
while two more f64 args are live, exercising pushargsrev's float spill
under XMM register pressure — a distinct path. Verified .s diverges on
master 6f8b658 (integer PUSHQ AX/POPQ DI for the myf.g() arg) and is
byte-identical post-fix; cstage run exits 8 (sum3(-7,10.5,4.5)=8.0:i32).
(#98)