Sketch in core zed actions code

crates/zed_actions2/src/lib.rs

@@ -1,5 +1,14 @@
 use gpui::{action, actions};
 
+// If the zed binary doesn't use anything in this crate, it will be optimized away
+// and the actions won't initialize. So we just provide an empty initialization function
+// to be called from main.
+//
+// These may provide relevant context:
+// https://github.com/rust-lang/rust/issues/47384
+// https://github.com/mmastrac/rust-ctor/issues/280
+pub fn init() {}
+
 actions!(
     About,
     DebugElements,