Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

claim-unused.c
// RUN: touch %t.o
// RUN: %clang --param ssp-buffer-size=1 %t.o -### 2>&1 | FileCheck %s
// CHECK-NOT: warning: argument unused during compilation: '--param ssp-buffer-size=1'