Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

PR8884.cpp
// RUN: %clang_cc1 -fsyntax-only  %s
extern "C" {
  class bar {
    friend struct foo;
    static struct foo& baz ();
  };
  struct foo {
    void zed () {
      bar::baz();
    }
  };
}