Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

empty.ll
; RUN: llvm-as < %s | llvm-dis > %t.orig
; RUN: llvm-as < %s | llvm-c-test --echo > %t.echo
; RUN: diff -w %t.orig %t.echo
; RUN: llvm-as < %s | llvm-c-test --test-diagnostic-handler 2>&1 | FileCheck %s
; CHECK: Diagnostic handler was not called while loading module