Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

macro_paste_spacing2.c
// RUN: %clang_cc1 %s -E | grep "movl %eax"
// PR4132
#define R1E %eax
#define epilogue(r1) movl r1 ## E;
epilogue(R1)