Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

mi_opt2.c
// RUN: %clang_cc1 -E %s | FileCheck %s
// PR6282
// This test should not trigger the include guard optimization since
// the guard macro is defined on the first include.

#define ITERATING 1
#define X 1
#include "mi_opt2.h"
#undef X
#define X 2
#include "mi_opt2.h"

// CHECK: b: 1
// CHECK: b: 2