Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

create.test
## Test the creation warning and supression of that warning.

RUN: touch %t1.txt
RUN: touch %t2.txt

RUN: rm -f %t.warning.ar
RUN: llvm-ar r %t.warning.ar %t1.txt %t2.txt 2>&1 \
RUN:   | FileCheck %s -DOUTPUT=%t.warning.ar

CHECK: warning: creating [[OUTPUT]]

RUN: rm -f %t.supressed.ar
RUN: llvm-ar cr %t.supressed.ar %t1.txt %t2.txt 2>&1 | count 0