Followup to 03039ab2ee.
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=58335
If I observed it right we currently leave `init_xstate_features` on older computers with EnabledFeatures being zero.
This leads in `__wine_syscall_dispatcher` to getting the xsave64 getting
called with "$rax = 0x0", therefore e.g. xmm6 gets not saved to the stack.
But later e.g. xmm6 gets restored from stack in `__wine_syscall_dispatcher` (see [](https://gitlab.winehq.org/wine/wine/-/blob/wine-10.12/dlls/ntdll/unix/signal_x86_64.c?ref_type=tags#L2774-L2882))
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https://gitlab.winehq.org/wine/wine/-/merge_requests/8591
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v2: server: Set IOSB for cancelled asyncs in async_terminate().
ntdll: Make wait in wait_async() always non-alertable.
ntdll: Factor out test_alert_with_status().
ntdll/tests: Add more tests for canceling synchronous IO.
https://gitlab.winehq.org/wine/wine/-/merge_requests/8592