Create a new channel as a copy of main.
Rename main to:
Delete main? This cannot be undone.
// RUN: %clang_cc1 -E -dM -ffreestanding -triple=arm64e-apple-ios < /dev/null | FileCheck %s // CHECK: #define __ARM64_ARCH_8__ 1 // CHECK: #define __arm64__ 1 // CHECK: #define __arm64e__ 1