Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

mh_dylib_header.test
RUN: llvm-objdump -d --macho %p/Inputs/mh_dylib_header.macho-arm

CHECK: _t1:
CHECK:     movw r0, #4133

CHECK: _a1:
CHECK:     bx lr