swift-mirror/test/Generics/redundant_requirement_self_conforming_protocol.swift

// RUN: %target-typecheck-verify-swift
// RUN: %target-swift-frontend -typecheck -debug-generic-signatures %s 2>&1 | %FileCheck %s

struct G<T> {}

// CHECK-LABEL: Generic signature: <T where T == any Error>
extension G where T : Error, T == Error {}