* src/x86/ffi64.c (struct register_args): Rename from stackLayout.
        (enum x86_64_reg_class): Add X86_64_COMPLEX_X87_CLASS.
        (merge_classes): Check for it.
        (SSE_CLASS_P): New.
        (classify_argument): Pass byte_offset by value; perform all updates
        inside struct case.
        (examine_argument): Add classes argument; handle
        X86_64_COMPLEX_X87_CLASS.
        (ffi_prep_args): Merge into ...
        (ffi_call): ... here.  Share stack frame with ffi_call_unix64.
        (ffi_prep_cif_machdep): Setup cif->flags for proper structure return.
        (ffi_fill_return_value): Remove.
        (ffi_prep_closure): Remove dead assert.
        (ffi_closure_unix64_inner): Rename from ffi_closure_UNIX64_inner.
        Rewrite to use struct register_args instead of va_list.  Create
        flags for handling structure returns.
        * src/x86/unix64.S: Remove dead strings.
        (ffi_call_unix64): Rename from ffi_call_UNIX64.  Rewrite to share
        stack frame with ffi_call.  Handle structure returns properly.
        (float2sse, floatfloat2sse, double2sse): Remove.
        (sse2float, sse2double, sse2floatfloat): Remove.
        (ffi_closure_unix64): Rename from ffi_closure_UNIX64.  Rewrite
        to handle structure returns properly.

From-SVN: r92602