Merge branch 'master' into reexporting_in_2018

crates/backend/src/codegen.rs

@@ -844,6 +844,18 @@ impl ToTokens for ast::ImportEnum {
                 }
             }
 
+            #[allow(clippy::all)]
+            impl wasm_bindgen::convert::OptionIntoWasmAbi for #name {
+                #[inline]
+                fn none() -> Self::Abi { Object::none() }
+            }
+
+            #[allow(clippy::all)]
+            impl wasm_bindgen::convert::OptionFromWasmAbi for #name {
+                #[inline]
+                fn is_none(abi: &Self::Abi) -> bool { Object::is_none(abi) }
+            }
+
             #[allow(clippy::all)]
             impl From<#name> for wasm_bindgen::JsValue {
                 fn from(obj: #name) -> wasm_bindgen::JsValue {