Implement support for derived IXmlSerializable types in XmlSerializer#129492

StephenMolloy merged 8 commits into

dotnet:maindotnet/runtime:mainfrom

StephenMolloy:1401-Handle-Derived-Mappings-in-Reflection-XmlSerializerStephenMolloy/runtime:1401-Handle-Derived-Mappings-in-Reflection-XmlSerializerCopy head branch name to clipboard