C#: For implicit constructors, pick a unique source location as reporting location (if any).

Author: michaelnebel

csharp/extractor/Semmle.Extraction.CSharp/Entities/Constructor.cs

@@ -222,7 +222,8 @@ public override Microsoft.CodeAnalysis.Location? ReportingLocation
 
                 if (Symbol.IsImplicitlyDeclared)
                 {
-                    return ContainingType!.ReportingLocation;
+                    var best = Symbol.Locations.Where(l => l.IsInSource).BestOrDefault();
+                    return best ?? ContainingType!.ReportingLocation;
                 }
 
                 return Symbol.ContainingType.Locations.FirstOrDefault();