TextEditor: request assist after trigger char inserted

... while proposal is shown

amends 23d63dcc8b

Fixes: QTCREATORBUG-24225
Change-Id: Ie935c7c1d4786a4fd3cf338d7f1df52ae28de63b
Reviewed-by: David Schulz <david.schulz@qt.io>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/clangcodemodel/clangeditordocumentprocessor.h

@@ -140,6 +140,7 @@ private:
     QFutureWatcher<void> m_parserWatcher;
     QTimer m_updateBackendDocumentTimer;
     unsigned m_parserRevision;
+    enum class InvalidationState { Off, Scheduled, Canceled } m_invalidationState;
 
     QVector<ClangBackEnd::TokenInfoContainer> m_tokenInfos;
     CppTools::SemanticHighlighter m_semanticHighlighter;