Ensure module attributes are applied to all modules.

Effectively revert bytecodealliance#1089, and go back to putting `#[allow(dead_code)]`
on all modules for now, because the code in bytecodealliance#1089 didn't work for
interfaces defined inline inside of worlds, which turn into top-level
modules in the Rust bindings.

Author: sunfishcode

crates/rust/src/lib.rs

@@ -296,20 +296,18 @@ impl RustWasm {
         emit(&mut self.src, map, &self.opts, true);
         fn emit(me: &mut Source, module: Module, opts: &Opts, toplevel: bool) {
             for (name, submodule) in module.submodules {
-                if toplevel {
-                    // Disable rustfmt. By default we already format the code
-                    // using prettyplease, so we don't want `cargo fmt` to create
-                    // extra diffs for users to deal with.
-                    if opts.format {
-                        uwriteln!(me, "#[rustfmt::skip]");
-                    }
-
-                    // Ignore dead-code and clippy warnings. If the bindings are
-                    // only used within a crate, and not exported to a different
-                    // crate, some parts may be unused, and that's ok.
-                    uwriteln!(me, "#[allow(dead_code, clippy::all)]");
+                // Disable rustfmt. By default we already format the code
+                // using prettyplease, so we don't want `cargo fmt` to create
+                // extra diffs for users to deal with.
+                if opts.format {
+                    uwriteln!(me, "#[rustfmt::skip]");
                 }
 
+                // Ignore dead-code and clippy warnings. If the bindings are
+                // only used within a crate, and not exported to a different
+                // crate, some parts may be unused, and that's ok.
+                uwriteln!(me, "#[allow(dead_code, clippy::all)]");
+
                 uwriteln!(me, "pub mod {name} {{");
                 emit(me, submodule, opts, false);
                 uwriteln!(me, "}}");