Create a new channel as a copy of main.
Rename main to:
Delete main? This cannot be undone.
; RUN: not llvm-as < %s -disable-output 2>&1 | FileCheck %s ; CHECK: <stdin>:[[@LINE+1]]:27: error: invalid debug info flag 'DIFlagUnknown' !0 = !DISubprogram(flags: DIFlagUnknown)