Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

tprel_noextend.s
# RUN: llvm-mc -arch=hexagon -filetype=obj %s | llvm-objdump -d - | FileCheck %s
#

# CHECK-NOT: immext
r0 = #undefined@TPREL

# CHECK-NOT: immext
r0 = #undefined@DTPREL