Execute callback-based and sync functions async
hronously without rewriting their definitions.
// Callback Conversion
// Before:
foo.bar("baz", completion: { (result: Int) in })
// After:
async let result: Int = await foo.bar >>> ("baz")
// Sync Conversion
// Before:
let result: Int = foo.bar("baz")
// After:
async let result: Int = await foo.bar >>> ("baz")