Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

ret_arg4.ll
; RUN: llc -mtriple=arm-eabi %s -o /dev/null

define i32 @test(i32 %a1, i32 %a2, i32 %a3, i32 %a4) {
        ret i32 %a4
}