Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

llvm_lit_site_cfg_files.gni
llvm_lit_site_cfg_file = "$root_gen_dir/llvm/test/lit.site.cfg.py"
llvm_lit_unit_site_cfg_file = "$root_gen_dir/llvm/test/Unit/lit.site.cfg.py"