Silence warnings on decltype() with Wine 5.22

There were already similar warnings on 32-bit winegcc, but now it also
happens on the 64-bit version. Instead of adding
`-Wno-ignored-attributes` we'll just sprinkle some warning ignores here
and there to prevent any other surprises.

src/wine-host/utils.h

@@ -181,12 +181,18 @@ class Win32Thread {
     Win32Thread& operator=(Win32Thread&&);
 
    private:
+    // FIXME: This emits `-Wignored-attributes` as of Wine 5.22
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wignored-attributes"
+
     /**
      * The handle for the thread that is running, will be a null pointer if this
      * class was constructed with the default constructor.
      */
     std::unique_ptr<std::remove_pointer_t<HANDLE>, decltype(&CloseHandle)>
         handle;
+
+#pragma GCC diagnostic pop
 };
 
 /**