Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

go.test
; RUN: llvm-go test llvm.org/llvm/bindings/go/llvm

; REQUIRES: shell, default_triple
;; Building Go bindings with Clang is currently unsupported on AIX.
; UNSUPPORTED: asan, ubsan, msan, -aix