Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

PR3709-int-to-pointer-sign.c
// RUN: %clang_cc1 -emit-llvm %s -o - -O1 -triple=x86_64-gnu-linux | grep "i64 -1"

// PR3709
long long a(void) { return (long long)(int*)-1;}