Move wasm test to a top-level module.

For some unknown reason, this makes rust-analyzer not angry.

src/wasm/mod.rs

@@ -9,8 +9,6 @@ mod clock;
 mod code;
 mod comment;
 mod comment_block;
-#[cfg(feature = "wasm_test")]
-pub mod compare;
 mod diary_sexp;
 mod document;
 mod drawer;