f265358fbe
In libfabric v1.0.0 (i.e., API v1.0), the usnic provider handled FI_MSG_PREFIX inconsistently between sends and receives. This has been fixed in libfabric v1.1.0 (i.e., API v1.1): FI_MSG_PREFIX is handled consistently for both sends and receives. Run-time detect which libfabric we are running with and adapt behavior appropriately.