ClangCodeModel: Relax completion result filtering

... in connect() calls.
The logic was: If we are in a place where a signal is expected and there
are signals among the completion results, then we should consider only
signals.
However, in e.g. a member function of a QObject subclass, there are
always signals in scope, even when we expect a class name. So we need to
allow class names as well.
Amends a79b0c6558.

Fixes: QTCREATORBUG-25153
Change-Id: Id3bbaaf4f8eefefe36cfc91e5959d3ef5ad28071
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/clangcodemodel/clangcompletionassistprocessor.cpp

@@ -139,15 +139,17 @@ QList<AssistProposalItemInterface *> ClangCompletionAssistProcessor::toAssistPro
         considerOnlySignals = CppTools::CppModelManager::instance()
                 ->positionRequiresSignal(m_interface->filePath().toString(), m_content, m_position);
     }
-
     for (const CodeCompletion &codeCompletion : completions) {
-        if (considerOnlySignals && codeCompletion.completionKind
-                != CodeCompletion::SignalCompletionKind) {
-            continue;
-        }
         if (codeCompletion.text.isEmpty())
             continue; // It's an OverloadCandidate which has text but no typedText.
 
+        if (considerOnlySignals
+                && codeCompletion.completionKind != CodeCompletion::ClassCompletionKind
+                && codeCompletion.completionKind != CodeCompletion::NamespaceCompletionKind
+                && codeCompletion.completionKind != CodeCompletion::SignalCompletionKind) {
+                continue;
+        }
+
         // Don't offer symbols that are not accessible here.
         if (codeCompletion.availability == CodeCompletion::NotAvailable
                 || codeCompletion.availability == CodeCompletion::NotAccessible) {