LSP: rerequest completion if contents change while processing

Task-number: QTCREATORBUG-21108
Change-Id: I6ca7920e7099dba0ba1bc953a2e6296bd86c1dc1
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/texteditor/codeassist/iassistprocessor.h

@@ -50,6 +50,7 @@ public:
     void setAsyncCompletionAvailableHandler(const AsyncCompletionsAvailableHandler &finalizer);
 
     virtual bool running() { return false; }
+    virtual bool needsRestart() const { return false; }
 
 private:
     AsyncCompletionsAvailableHandler m_asyncCompletionsAvailableHandler;