[PATCH v2 0/2] MR9398: Don't try to activate a window in set_window_pos if it's set as active in GUITHREADINFO.

[Santino Mazza (＠tati)]

This prevents a window from getting reactivated when calling `SetWindowPos` inside the WM_ACTIVATE handler. For now I only was able to reproduce this by triggering a change in the active window from X11 with an alt-tab or by clicking another window, I was not able to write a wine test for this.

This test program works for reproducing it.
```c
#include <windows.h>

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
    if (uMsg == WM_ACTIVATE) {
        SetWindowPos(hwnd, 0, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE);
    }

done:
    return DefWindowProc(hwnd, uMsg, wParam, lParam);
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR pCmdLine,
                   int nCmdShow) {
    HWND hwnd;
    const char CLASS_NAME[] = "class";
    WNDCLASSA wc = {};
    wc.lpfnWndProc = WindowProc;
    wc.hInstance = hInstance;
    wc.lpszClassName = CLASS_NAME;

RegisterClass(&wc);

hwnd =
    CreateWindowEx(0, CLASS_NAME, "test", 0,
                    4, 4, 1024, 768, NULL, NULL, hInstance, NULL);

ShowWindow(hwnd, SW_SHOW);

MSG msg;
    while (TRUE) {
        GetMessage(&msg, NULL, 0, 0);
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
}
```

--
  v2: win32u: Don't activate a window that is being deactivated.
      win32u: Set WIN_IS_DEACTIVATING for previous window.

https://gitlab.winehq.org/wine/wine/-/merge_requests/9398