Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

attr-cleanup.c
// RUN: %clang_cc1 -emit-llvm %s -o %t

// <rdar://problem/6827047>
void f(void* arg);
void g(void) {
  __attribute__((cleanup(f))) void *g;
}