Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

2004-12-12-ZeroSizeCommon.ll
; RUN: llc -verify-machineinstrs < %s -mtriple=ppc32-- | not grep .comm.*X,0

@X = linkonce global {  } zeroinitializer               ; <{  }*> [#uses=0]