Minor. Add covariant override for TypeParameterDescriptor.original

compiler/frontend/src/org/jetbrains/kotlin/resolve/TypeResolver.kt

@@ -671,7 +671,7 @@ class TypeResolver(
             fromIndex: Int,
             constructorParameters: List<TypeParameterDescriptor>
     ) = constructorParameters.subList(fromIndex, constructorParameters.size).map {
-        TypeProjectionImpl((it.original as TypeParameterDescriptor).defaultType)
+        TypeProjectionImpl(it.original.defaultType)
     }
 
     fun resolveTypeProjections(

core/descriptors/src/org/jetbrains/kotlin/descriptors/TypeParameterDescriptor.java

@@ -42,6 +42,10 @@ public interface TypeParameterDescriptor extends ClassifierDescriptor {
     @Deprecated // Use the static method DescriptorSubstitutor.substituteTypeParameters()
     TypeParameterDescriptor substitute(@NotNull TypeSubstitutor substitutor);
 
+    @NotNull
+    @Override
+    TypeParameterDescriptor getOriginal();
+
     int getIndex();
 
     /**

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/AbstractTypeParameterDescriptor.java

@@ -128,6 +128,12 @@ public abstract class AbstractTypeParameterDescriptor extends DeclarationDescrip
         return defaultType.invoke();
     }
 
+    @NotNull
+    @Override
+    public TypeParameterDescriptor getOriginal() {
+        return (TypeParameterDescriptor) super.getOriginal();
+    }
+
     @NotNull
     @Override
     @Deprecated