Workaround for opt-gcc compiler bug
Workaround for opt-gcc compiler bug

Summary: This diff appears to work around a compiler bug in gcc10 with coroutines. GCC is not keeping alive a temporary passed to a coroutine function.

Reviewed By: nmagerko

Differential Revision: D29847926

fbshipit-source-id: 69e0fc4cece8f5d0e26647581800ad81b1e44c74

facebook/folly,facebook/folly,facebook/folly,facebook/folly,facebook/folly