CppTools: Turn some classes into pure value types

ProjectInfo, ProjectPart and ProjectUpdateInfo used to carry pointers
to Project and/or Toolchain, even though they were used in contexts
where these pointers were either unsafe to access or not guaranteed to
be valid anymore, which made their use difficult and error-prone.
We turn these classes into pure value types by copying in all relevant
information before the first async operation takes place.

Fixes: QTCREATORBUG-25678
Change-Id: I1914b0dbda6c7dfba6c95e5e92f2d69977755590
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/plugins/projectexplorer/session.cpp

@@ -703,6 +703,12 @@ Project *SessionManager::projectForFile(const Utils::FilePath &fileName)
                                 [&fileName](const Project *p) { return p->isKnownFile(fileName); });
 }
 
+Project *SessionManager::projectWithProjectFilePath(const Utils::FilePath &filePath)
+{
+    return Utils::findOrDefault(SessionManager::projects(),
+            [&filePath](const Project *p) { return p->projectFilePath() == filePath; });
+}
+
 void SessionManager::configureEditor(IEditor *editor, const QString &fileName)
 {
     if (auto textEditor = qobject_cast<TextEditor::BaseTextEditor*>(editor)) {