ClangTools: Add automatic clang tool runner for open documents

Fixes: QTCREATORBUG-23349
Change-Id: I81197180c9d69c7df6184f8fcbf05f2256eaf7f6
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/clangtools/clangtoolsplugin.h

@@ -27,6 +27,7 @@
 
 #include <extensionsystem/iplugin.h>
 
+namespace Core { class IDocument; }
 namespace ProjectExplorer { class ProjectPanelFactory; }
 
 namespace ClangTools {
@@ -46,6 +47,7 @@ public:
 private:
     bool initialize(const QStringList &arguments, QString *errorString) final;
     void registerAnalyzeActions();
+    void onCurrentEditorChanged();
 
     QVector<QObject *> createTestObjects() const final;