os.NewFile() accounts for 38% of CPU time in localFile.Walk().
This change switchs to use fd.FD which is much cheaper to create.
Now, fd.New() in localFile.Walk() accounts for only 4%.
PiperOrigin-RevId: 244944983
Change-Id: Ic892df96cf2633e78ad379227a213cb93ee0ca46
Prevents URPC FDs from being closed mid-call, especially if they
are used as raw FDs.
PiperOrigin-RevId: 233087955
Change-Id: I815a2ff32cc5f03774605aef0b35a32862f8e633
Fabricio Voznika
Christopher Koch
Ian Gudger
Googler