QMakeProjectManager: Use ProjectPartBuilder

...as the other project managers.

This removes extra code paths, duplication and improves classification
of source files (ambiguous headers).

Change-Id: Iae05cbbc61ab2e5dd841ae617bec994e0a1e52d5
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/cpptools/cppbaseprojectpartbuilder.h

@@ -60,13 +60,12 @@ public:
 
     void setPreCompiledHeaders(const QStringList &preCompiledHeaders);
 
+    void setSelectedForBuilding(bool yesno);
+
     using FileClassifier = std::function<ProjectFile::Kind (const QString &filePath)>;
     QList<Core::Id> createProjectPartsForFiles(const QStringList &filePaths,
                                                FileClassifier fileClassifier = FileClassifier());
 
-    static void evaluateToolChain(ProjectPart &projectPart,
-                                  const ToolChainInterface &selectToolChain);
-
 private:
     void createProjectPart(const ProjectFiles &projectFiles,
                            const QString &partName,