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

RUN: rm -f %t.ar
RUN: llvm-ar crs %t.ar %t.o
RUN: grep -q __.SYMDEF %t.ar

Ensure that we generate a BSD style archive for MachO by default.  ld64 expects
that it will be in BSD format.