[Bug target/59794] i386 backend fails to detect SSE/AVX return value

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59794

--- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> ---
Created attachment 31826
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31826&action=edit
A patch

I am testing this patch.