XCB: also test for Xinerama's presence

It's included unconditionally from qxcbconnection.cpp and qxcbscreen.h.

Task-number: QTBUG-53537
Change-Id: I6e1fe42ae4b742a7b811fffd14e5d374155660f3
Reviewed-by: Gatis Paeglis <gatis.paeglis@qt.io>

src/gui/configure.json

@@ -433,6 +433,7 @@
                     "xcb/xfixes.h",
                     "xcb/xcb_image.h",
                     "xcb/xcb_keysyms.h",
+                    "xcb/xinerama.h",
                     "xcb/sync.h",
                     "xcb/randr.h",
                     "xcb/shm.h"
@@ -450,8 +451,8 @@
             },
             "sources": [
                 { "type": "pkgConfig",
-                  "args": "xcb xcb-shm xcb-sync xcb-xfixes xcb-randr xcb-image xcb-keysyms xcb-icccm xcb-shape" },
-                "-lxcb -lxcb-shm -lxcb-sync -lxcb-xfixes -lxcb-randr -lxcb-image -lxcb-keysyms -lxcb-icccm -lxcb-shape"
+                  "args": "xcb xcb-shm xcb-sync xcb-xfixes xcb-xinerama xcb-randr xcb-image xcb-keysyms xcb-icccm xcb-shape" },
+                "-lxcb -lxcb-shm -lxcb-sync -lxcb-xfixes -lxcb-xinerama -lxcb-randr -lxcb-image -lxcb-keysyms -lxcb-icccm -lxcb-shape"
             ]
         },
         "xcb_xlib": {

src/plugins/platforms/xcb/xcb_qpa_lib.pro

@@ -69,7 +69,6 @@ include(gl_integrations/gl_integrations.pri)
 !qtConfig(system-xcb) {
     QMAKE_USE += xcb-static xcb
 } else {
-    LIBS += -lxcb-xinerama  ### there is no configure test for this!
     qtConfig(xkb): QMAKE_USE += xcb_xkb
     qtConfig(xcb-render): QMAKE_USE += xcb_render
     QMAKE_USE += xcb_syslibs