Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

registers_readonly.s
# RUN: not llvm-mc -arch=hexagon -filetype=obj %s 2>&1 | FileCheck %s

# CHECK: 4:3: error: Cannot write to read-only register `PC'
{ pc = r0
  r0 = r0 }