Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

directive_line.s
# RUN: llvm-mc -triple i386-unknown-unknown %s
# RUN: llvm-mc -triple i386-unknown-unknown %s -filetype=null
# FIXME: Actually test the output.

        .line
        .line 1