Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

windows-nul.c
// RUN: %clang_cc1 nul

// REQUIRES: system-windows

// Verify that cc1 doesn't crash with an assertion failure
// in MemoryBuffer.cpp due to an invalid file size reported
// when the Windows 'nul' device is passed in input.