revert workaround for alloc and free as coro params

reverts 4ac6c4d6bfb8f7ada2799ddb5ce3a9797be0518d

the workaround didn't work
138d6f9093Andrew Kelley committed on 2/27/2018, 10:46:13 PMparent132e604
5 files changedLine totals unavailable