Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

exec-all-runlines.test
## Test that non-clang/non-filechecked runlines execute

# RUN: cp %S/Inputs/exec-all-runlines.c %t-generated.c && %update_cc_test_checks %t-generated.c
# RUN: diff -u %S/Inputs/exec-all-runlines.c.expected %t-generated.c

## Check that re-running update_cc_test_checks doesn't change the output
# RUN: %update_cc_test_checks %t-generated.c
# RUN: diff -u %S/Inputs/exec-all-runlines.c.expected %t-generated.c