ptrace: add PTRACE_O_EXITKILL option
ptrace: add PTRACE_O_EXITKILL option

It is a somewhat newer option -- it requires Linux 3.8.

Susurrus/nix,geofft/nix-rust,carllerche/nix-rust,carllerche/nix-rust,Susurrus/nix,geofft/nix-rust,asomers/nix,xd009642/nix,MarkusJais/nix-rust,MarkusJais/nix-rust,xd009642/nix,geofft/nix-rust,xd009642/nix,nix-rust/nix,MarkusJais/nix-rust,asomers/nix,carllerche/nix-rust,Susurrus/nix,nix-rust/nix