Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

crash-if-directive.cpp
#define FOO(X) X
#if FOO(
#elif FOO(
#endif
// RUN: %clang_cc1 -fsyntax-only -code-completion-at=%s:2:9 %s
// RUN: not %clang_cc1 -fsyntax-only -code-completion-at=%s:3:11 %s