Merge pull request swiftlang#84065 from adrian-prantl/virtual-6.2

[demangling] make printGenericSignature virtual

Author: shahmishal

include/swift/Demangling/Demangle.h

@@ -949,7 +949,7 @@ class NodePrinter {
 
   void printImplFunctionType(NodePointer fn, unsigned depth);
 
-  void printGenericSignature(NodePointer Node, unsigned depth);
+  virtual void printGenericSignature(NodePointer Node, unsigned depth);
 
   void printFunctionSigSpecializationParams(NodePointer Node, unsigned depth);