Add EpollCrateFlags bitflag type.
Add EpollCrateFlags bitflag type.

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