Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

codeview-merging-cycle.test
; RUN: not llvm-readobj --codeview-merged-types %S/Inputs/codeview-cycle.obj 2>&1 | FileCheck %s

; CHECK: error{{.*}} Input type graph contains cycles

; To reproduce codeview-cycle.obj:
; $ cat codeview-cycle.asm
;       .model  flat, C
;       .code
; pfoo_list TYPEDEF PTR foo_list
; foo_list STRUCT
;       next pfoo_list ?
;       data dd ?
; foo_list ENDS
;       public  foo
; foo proc dst:ptr foo_list
;       ret
; foo   endp
;       end
; $ ml -c -Zi codeview-cycle.asm