Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

x86-condbr.test
# REQUIRES: x86-registered-target
## Check that update_mir_test_checks uses CHECK-NEXT directories

# RUN: cp -f %S/Inputs/x86-condbr.mir %t.mir && %update_mir_test_checks %t.mir
# RUN: diff -u %S/Inputs/x86-condbr.mir.expected %t.mir