https://fuchsia.googlesource.com/third_party/swift-clang/+/refs/tags/swift-DEVELOPMENT-SNAPSHOT-2016-09-30-a/test/CodeGenCXX/friend-redecl.cpp?autodive=0%2F%2F%2F%2F%2F%2F%2F%2F%2F
test/CodeGenCXX/friend-redecl.cpp - third_party/swift-clang - Git at Google
third party