Related tdf#126459: fix crash in presenter console using gen vclplug

A slide with video is needed to reproduce

Regression from commit ac87cfdf263d2abd97b32857534d0f749b7c4479,
'toolkit' and 'platform' bits were never set (bc irrelevant) in gen
vclplug but now if not set, values mapping to 0 (Gtk3, Wayland) will
be used and things go down the drain in avmedia/gstplayer then

Just between us girls, nobody in their right mind would use gen vclplug
for presentation, but crash is not nice so let's fix this

Change-Id: If318ab93897f9f4854f7316e630c35aaec2480fd
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/87185
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
diff --git a/include/vcl/sysdata.hxx b/include/vcl/sysdata.hxx
index 41277c5..89122f5 100644
--- a/include/vcl/sysdata.hxx
+++ b/include/vcl/sysdata.hxx
@@ -61,7 +61,7 @@ struct SystemEnvData
#elif defined( IOS )
    // Nothing
#elif defined( UNX )
    enum class Toolkit { Gtk3, Qt5 };
    enum class Toolkit { Gtk3, Qt5, Gen };
    enum class Platform { Wayland, Xcb };

    void*               pDisplay;       // the relevant display connection
diff --git a/vcl/unx/generic/window/salframe.cxx b/vcl/unx/generic/window/salframe.cxx
index 0275d1e..b618ab8 100644
--- a/vcl/unx/generic/window/salframe.cxx
+++ b/vcl/unx/generic/window/salframe.cxx
@@ -956,6 +956,8 @@ const SystemEnvData* X11SalFrame::GetSystemData() const
    pFrame->maSystemChildData.pVisual       = GetDisplay()->GetVisual( m_nXScreen ).GetVisual();
    pFrame->maSystemChildData.nScreen       = m_nXScreen.getXScreen();
    pFrame->maSystemChildData.aShellWindow  = pFrame->GetShellWindow();
    pFrame->maSystemChildData.toolkit       = SystemEnvData::Toolkit::Gen;
    pFrame->maSystemChildData.platform      = SystemEnvData::Platform::Xcb;
    return &maSystemChildData;
}

diff --git a/vcl/unx/generic/window/salobj.cxx b/vcl/unx/generic/window/salobj.cxx
index c571936..b19dd61 100644
--- a/vcl/unx/generic/window/salobj.cxx
+++ b/vcl/unx/generic/window/salobj.cxx
@@ -225,6 +225,8 @@ X11SalObject::X11SalObject()
    maSystemChildData.pWidget       = nullptr;
    maSystemChildData.pVisual       = nullptr;
    maSystemChildData.aShellWindow  = 0;
    maSystemChildData.toolkit = SystemEnvData::Toolkit::Gen;
    maSystemChildData.platform = SystemEnvData::Platform::Xcb;

    std::list< SalObject* >& rObjects = vcl_sal::getSalDisplay(GetGenericUnixSalData())->getSalObjects();
    rObjects.push_back( this );