Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

cxx-offsetof-base.cpp
// RUN: %clang_cc1 -x c++-header -emit-pch -o %t %S/cxx-offsetof-base.h
// RUN: %clang_cc1 -include-pch %t -fsyntax-only %s