Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

image-info.test
# RUN: llvm-mc < %s --triple x86_64-darwin -filetype=obj | llvm-objdump --macho --objc-meta-data - | FileCheck %s

.section	__DATA,__objc_imageinfo,regular,no_dead_strip
.long	0
.long	96

# CHECK: OBJC_IMAGE_IS_SIMULATED OBJC_IMAGE_HAS_CATEGORY_CLASS_PROPERTIES