hw/xwin: Update for glxvnd

- Link with libglxvnd in meson.build
- Call xorgGlxCreateVendor() like all other DDX

Signed-off-by: Jon Turney <jon.turney@dronecode.org.uk>

hw/xwin/InitOutput.c

@@ -1012,6 +1012,8 @@ InitOutput(ScreenInfo * pScreenInfo, int argc, char *argv[])
         }
     }
 
+    xorgGlxCreateVendor();
+
     /* Generate a cookie used by internal clients for authorization */
     if (g_fXdmcpEnabled || g_fAuthEnabled)
         winGenerateAuthorization();

hw/xwin/meson.build

@@ -149,6 +149,7 @@ executable(
         libxserver_fb,
         libxserver,
         libxserver_glx,
+        libglxvnd,
         libxserver_xkb_stubs,
         libxserver_miext_shadow,
         libxserver_pseudoramix,