Base: Add missing const to Type::createInstance

src/Base/Type.cpp

@@ -59,7 +59,7 @@ map<string, unsigned int> Type::typemap;
 vector<TypeData*> Type::typedata;
 set<string> Type::loadModuleSet;
 
-void* Type::createInstance()
+void* Type::createInstance() const
 {
     instantiationMethod method = typedata[index]->instMethod;
     return method ? (*method)() : nullptr;

src/Base/Type.h

@@ -88,7 +88,7 @@ public:
     ~Type() = default;
 
     /// creates a instance of this type
-    void* createInstance();
+    void* createInstance() const;
     /// Checks whether this type can instantiate
     bool canInstantiate() const;
     /// creates a instance of the named type