Add WebIDL support for the ArrayBuffer type

Should help enable a slew of new bindings as well.

crates/webidl/src/lib.rs

@@ -102,6 +102,7 @@ fn compile_ast(mut ast: backend::ast::Program) -> String {
         vec![
             "str", "char", "bool", "JsValue", "u8", "i8", "u16", "i16", "u32", "i32", "u64", "i64",
             "usize", "isize", "f32", "f64", "Result", "String", "Vec", "Option",
+            "ArrayBuffer",
         ].into_iter()
             .map(|id| proc_macro2::Ident::new(id, proc_macro2::Span::call_site())),
     );

crates/webidl/src/util.rs

@@ -422,9 +422,16 @@ impl<'a> FirstPassRecord<'a> {
                 }
             }
 
+            // This seems like a "naively correct" mapping, but the online docs
+            // are a bit scary in this regard...
+            //
+            // https://heycam.github.io/webidl/#es-buffer-source-types
+            webidl::ast::TypeKind::ArrayBuffer => {
+                simple_path_ty(vec![rust_ident("js_sys"), rust_ident("ArrayBuffer")])
+            }
+
             // Support for these types is not yet implemented, so skip
             // generating any bindings for this function.
-            webidl::ast::TypeKind::ArrayBuffer
             | webidl::ast::TypeKind::DataView
             | webidl::ast::TypeKind::Error
             | webidl::ast::TypeKind::FrozenArray(_)