[NFC][Coro] Use CloneFunctionInto for coroutine cloning instead of CloneFunction<Part> (#129149)

Summary:
CloneFunctionInto now is fast on its own and we don't need to use
CloneFunctionAttributes/Metadata/Body separately.

CommonDebugInfo in CoroClone is now unused and is cleaned up separately
in the next diff in the stack.

Test Plan:
ninja check-all

GitOrigin-RevId: 841f4637a078ce9adc5ef45f533a43bf7fbc7fc7
1 file changed