CppTools: Provide hints about chosen project part for editor document

Parse issues can have multiple reasons (invalid kit, not a project file,
actual parse issue) and we should be able to tell them apart. With this
change, we can distinguish between the fallback project part and a
ambiguous project part.

Follow up changes will use this to display more accurate diagnostics.

Change-Id: Icc8767607cc17dc14d6227b07f34e81ba5525a96
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/clangcodemodel/clangeditordocumentparser.cpp

@@ -39,12 +39,13 @@ void ClangEditorDocumentParser::updateImpl(const QFutureInterface<void> &,
                                            const UpdateParams &updateParams)
 {
     State state_ = state();
-    state_.projectPart = determineProjectPart(filePath(),
-                                              configuration(),
-                                              state_,
-                                              updateParams.activeProject,
-                                              updateParams.languagePreference,
-                                              updateParams.hasActiveProjectChanged);
+    state_.projectPartInfo = determineProjectPart(filePath(),
+                                                  configuration(),
+                                                  state_,
+                                                  updateParams.activeProject,
+                                                  updateParams.languagePreference,
+                                                  updateParams.hasActiveProjectChanged);
+    emit projectPartInfoUpdated(state_.projectPartInfo);
     setState(state_);
 }