* src/x86/ffi64.c (ffi_prep_cif_machdep): Save sse-used flag in
        bit 11 of flags.
        (ffi_call): Mask return type field.  Pass ssecount to ffi_call_unix64.
        (ffi_prep_closure): Set carry bit if sse-used flag set.
        * src/x86/unix64.S (ffi_call_unix64): Add ssecount argument.
        Only load sse registers if ssecount non-zero.
        (ffi_closure_unix64): Only save sse registers if carry set on entry.

From-SVN: r99257