Add FcntlArg::F_FULLFSYNC
Add FcntlArg::F_FULLFSYNC

https://developer.apple.com/library/ios/documentation/System/Conceptual/ManPages_iPhoneOS/man2/fsync.2.html

xd009642/nix,Susurrus/nix,carllerche/nix-rust,MarkusJais/nix-rust,Susurrus/nix,xd009642/nix,geofft/nix-rust,geofft/nix-rust,MarkusJais/nix-rust,geofft/nix-rust,xd009642/nix,kamalmarhubi/nix-rust,berkowski/nix,berkowski/nix,posborne/rust-nix,kamalmarhubi/nix-rust,MarkusJais/nix-rust,Susurrus/nix,kamalmarhubi/nix-rust,posborne/rust-nix,posborne/rust-nix,asomers/nix,berkowski/nix,carllerche/nix-rust,nix-rust/nix,asomers/nix,carllerche/nix-rust,nix-rust/nix