Handle creating ParameterMirrors for the parameters of forwarding constructors.

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index 1b2da1488c96c1356dd41add5600163577625ef1..4eba365688994976e89bf97f6a7ad7f85fa638ff 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -819,8 +819,8 @@ class Class : public Object {
   RawType* mixin() const { return raw_ptr()->mixin_; }
   void set_mixin(const Type& value) const;
 
+  // Note this returns false for mixin application aliases.
   bool IsMixinApplication() const;
-  bool IsAnonymousMixinApplication() const;
 
   RawClass* patch_class() const {
     return raw_ptr()->patch_class_;