Vendor dependencies

Let's see how I like this workflow.

vendor/wasm-bindgen-macro/ui-tests/invalid-items.rs

@@ -0,0 +1,33 @@
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen]
+fn foo() {}
+
+#[wasm_bindgen]
+pub const fn foo2() {}
+
+#[wasm_bindgen]
+struct Foo<T>(T);
+
+#[wasm_bindgen]
+extern "C" {
+    static mut FOO: u32;
+
+    pub fn foo3(x: i32, ...);
+}
+
+#[wasm_bindgen]
+extern "system" {
+}
+
+#[wasm_bindgen]
+pub fn foo4<T>() {}
+#[wasm_bindgen]
+pub fn foo5<'a>() {}
+#[wasm_bindgen]
+pub fn foo6<'a, T>() {}
+
+#[wasm_bindgen]
+trait X {}
+
+fn main() {}