Vendor dependencies

Let's see how I like this workflow.

vendor/wasm-bindgen-macro/ui-tests/invalid-methods.stderr

@@ -0,0 +1,61 @@
+error: #[wasm_bindgen] default impls are not supported
+ --> $DIR/invalid-methods.rs:7:1
+  |
+7 | default impl A {
+  | ^^^^^^^
+
+error: #[wasm_bindgen] unsafe impls are not supported
+  --> $DIR/invalid-methods.rs:11:1
+   |
+11 | unsafe impl A {
+   | ^^^^^^
+
+error: #[wasm_bindgen] trait impls are not supported
+  --> $DIR/invalid-methods.rs:15:6
+   |
+15 | impl Clone for A {
+   |      ^^^^^
+
+error: #[wasm_bindgen] generic impls aren't supported
+  --> $DIR/invalid-methods.rs:19:5
+   |
+19 | impl<T> A {
+   |     ^^^
+
+error: unsupported self type in #[wasm_bindgen] impl
+  --> $DIR/invalid-methods.rs:23:6
+   |
+23 | impl &'static A {
+   |      ^^^^^^^^^^
+
+error: const definitions aren't supported with #[wasm_bindgen]
+  --> $DIR/invalid-methods.rs:30:5
+   |
+30 |     const X: u32 = 3;
+   |     ^^^^^^^^^^^^^^^^^
+
+error: type definitions in impls aren't supported with #[wasm_bindgen]
+  --> $DIR/invalid-methods.rs:31:5
+   |
+31 |     type Y = u32;
+   |     ^^^^^^^^^^^^^
+
+error: macros in impls aren't supported
+  --> $DIR/invalid-methods.rs:32:5
+   |
+32 |     x!();
+   |     ^^^^^
+
+error: can only #[wasm_bindgen] non-const functions
+  --> $DIR/invalid-methods.rs:39:9
+   |
+39 |     pub const fn foo() {}
+   |         ^^^^^
+
+warning: unused macro definition
+  --> $DIR/invalid-methods.rs:26:1
+   |
+26 | macro_rules! x { () => () }
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(unused_macros)]` on by default