Create a new channel as a copy of main.
Rename main to:
Delete main? This cannot be undone.
; RUN: opt < %s -passes=instcombine -S | not grep "sub i32 0" ; PR2330 define i32 @foo(i32 %a) nounwind { entry: %A = sub i32 5, %a %B = and i32 %A, 2 ret i32 %B }