Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

debug-empty-source.s
// XFAIL: -aix
// UNSUPPORTED: -zos
// REQUIRES: object-emission
// RUN: llvm-mc %s -o -| FileCheck %s

.file 1 "dir1" "foo" source ""

# CHECK: .file {{.*}} source ""