Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

default-elf.test
RUN: yaml2obj %S/Inputs/elf.yaml -o %t.o

RUN: rm -f %t.ar
RUN: llvm-ar crs %t.ar %t.o
RUN: not grep -q __.SYMDEF %t.ar

Ensure that we generate a GNU style archive for ELF by default.  The GNU linker
expects that it will be in GNU format.