Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

cmpxchg-ordering.ll
; RUN: not llvm-as < %s 2>&1 | FileCheck %s

define void @f(i32* %a, i32 %b, i32 %c) {
; CHECK: invalid cmpxchg success ordering
  %x = cmpxchg i32* %a, i32 %b, i32 %c unordered monotonic
  ret void
}