ProjectExplorer: Give build systems a name

... and make it accessible through a variable.

Fixes: QTCREATORBUG-26147
Change-Id: I0601c09a74360b91fe8421876207a8f4ae9d75b6
Reviewed-by: hjk <hjk@qt.io>

src/plugins/mesonprojectmanager/project/mesonbuildsystem.h

@@ -48,6 +48,7 @@ public:
     ~MesonBuildSystem() final;
 
     void triggerParsing() final;
+    QString name() const final { return QLatin1String("meson"); }
 
     inline const BuildOptionsList &buildOptions() const { return m_parser.buildOptions(); }
     inline const TargetsList &targets() const { return m_parser.targets(); }