is this an instance of the 16-byte struct bug

[jerro]

> Then it look like a dmd backend bug. Can you post the generated 
> assembly ?

000000000043050c <_Dmain>:
    43050c:       push   %rbp
    43050d:       mov    %rsp,%rbp
    430510:       sub    $0x40,%rsp
    430514:       movabs $0x3ff0000000000000,%rax
    43051b:
    43051e:       mov    %rax,-0x40(%rbp)
    430522:       movsd  -0x40(%rbp),%xmm0
    430527:       rex.W movsd %xmm0,-0x30(%rbp)
    43052d:       xor    %edx,%edx
    43052f:       mov    %rax,-0x10(%rbp)
    430533:       mov    %rdx,-0x8(%rbp)
    430537:       mov    %rax,-0x28(%rbp)
    43053b:       mov    %rdx,-0x20(%rbp)
    43053f:       mov    0x28022(%rip),%rdx
    430546:       mov    0x28013(%rip),%rsi
    43054d:       mov    -0x28(%rbp),%rdi
    430551:       callq  430874 <void
std.stdio.writefln!(immutable(char)[],
ulong).writefln(immutable(char)[], ulong)>
    430556:       xor    %eax,%eax
    430558:       leaveq
    430559:       retq