Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

armv8.5a-sb.txt
# RUN: llvm-mc -triple=aarch64-none-linux-gnu -mattr=+sb -disassemble < %s      | FileCheck %s
# RUN: llvm-mc -triple=aarch64-none-linux-gnu -mattr=+v8.5a    -disassemble < %s      | FileCheck %s
# RUN: llvm-mc -triple=aarch64-none-linux-gnu -mattr=-sb -disassemble < %s 2>&1 | FileCheck %s --check-prefix=NOSB

# New reg
0xff 0x30 0x03 0xd5

# CHECK: sb
# NOSB:  msr S0_3_C3_C0_7, xzr