Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

vendor/rustix/src/backend/libc/event/mod.rs

@@ -0,0 +1,9 @@
+pub(crate) mod poll_fd;
+#[cfg(not(windows))]
+pub(crate) mod types;
+
+#[cfg_attr(windows, path = "windows_syscalls.rs")]
+pub(crate) mod syscalls;
+
+#[cfg(linux_kernel)]
+pub mod epoll;