ProjectExplorer: De-virtualize some more virtual methods

Use setters/getters for the bool flags in
Project::needsBuildConfigurations() and
Project::hasMakeInstallEquivalent.

Change-Id: I5ce937c3a5e8e0db627cda02a9007f8c28ccda0c
Reviewed-by: hjk <hjk@qt.io>

src/plugins/qmakeprojectmanager/qmakeproject.cpp

@@ -130,6 +130,7 @@ QmakeProject::QmakeProject(const FilePath &fileName) :
     setProjectLanguages(Core::Context(ProjectExplorer::Constants::CXX_LANGUAGE_ID));
     setDisplayName(fileName.toFileInfo().completeBaseName());
     setCanBuildProducts();
+    setHasMakeInstallEquivalent(true);
 
     const QTextCodec *codec = Core::EditorManager::defaultTextCodec();
     m_qmakeVfs->setTextCodec(codec);