Enable QML debugging only if project includes a qml library

Use the same check as in the DebuggerRunConfigurationAspect to
decide whether to  enable qml debugging, or not. This allows
us to follow the qmakestep setting in the run settings in a
follow-up change.

Task-number: QTCREATORBUG-11474
Change-Id: I67900cf719a56c0246e792c6aca66ce8e5d77daf
Reviewed-by: Eike Ziller <eike.ziller@digia.com>
Reviewed-by: Alessandro Portale <alessandro.portale@digia.com>

src/plugins/qmakeprojectmanager/qmakestep.cpp

@@ -44,6 +44,7 @@
 #include <projectexplorer/toolchain.h>
 
 #include <coreplugin/icore.h>
+#include <coreplugin/icontext.h>
 #include <qtsupport/debugginghelperbuildtask.h>
 #include <qtsupport/qtkitinformation.h>
 #include <qtsupport/qtversionmanager.h>
@@ -367,6 +368,10 @@ bool QMakeStep::linkQmlDebuggingLibrary() const
         return true;
     if (m_linkQmlDebuggingLibrary == DoNotLink)
         return false;
+
+    const Core::Context languages = project()->projectLanguages();
+    if (!languages.contains(ProjectExplorer::Constants::LANG_QMLJS))
+        return false;
     return (qmakeBuildConfiguration()->buildType() & BuildConfiguration::Debug);
 }