ADS: Only build if QmlDesigner is enabled

Change-Id: I8ca3bd5fab714e003ad05e502e5759f06ca77fed
Reviewed-by: Cristian Adam <cristian.adam@qt.io>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/libs/libs.pro

@@ -3,7 +3,6 @@ include(../../qtcreator.pri)
 TEMPLATE  = subdirs
 
 SUBDIRS   += \
-    advanceddockingsystem \
     aggregation \
     extensionsystem \
     utils \
@@ -24,6 +23,13 @@ qtHaveModule(quick) {
         tracing
 }
 
+QTC_DO_NOT_BUILD_QMLDESIGNER = $$(QTC_DO_NOT_BUILD_QMLDESIGNER)
+isEmpty(QTC_DO_NOT_BUILD_QMLDESIGNER):qtHaveModule(quick-private) {
+    exists($$[QT_INSTALL_QML]/QtQuick/Controls/qmldir) {
+        SUBDIRS += advanceddockingsystem
+    }
+}
+
 for(l, SUBDIRS) {
     QTC_LIB_DEPENDS =
     include($$l/$${l}_dependencies.pri)