GCS: enable to invalidate diagnosis result

src/Mod/Sketcher/App/planegcs/GCS.cpp

@@ -548,6 +548,13 @@ void System::clear()
     p2c.clear();
 }
 
+void System::invalidatedDiagnosis()
+{
+    hasDiagnosis=false;
+    pDependentParameters.clear();
+    pDependentParametersGroups.clear();
+}
+
 void System::clearByTag(int tagId)
 {
     std::vector<Constraint *> constrvec;

src/Mod/Sketcher/App/planegcs/GCS.h

@@ -366,6 +366,7 @@ namespace GCS
         void getDependentParamsGroups(std::vector<std::set<double *>> &pdependentparametergroups) const
           { pdependentparametergroups = pDependentParametersGroups;}
         bool isEmptyDiagnoseMatrix() const {return emptyDiagnoseMatrix;}
+        void invalidatedDiagnosis();
     };