Add /** @deferred */ comments to deferred callback parameters

src/build/emitter.ts

@@ -230,6 +230,8 @@
     getParentsWithConstant,
   );
 
+  const deferredParameterNames = new Set(["handler", "listener", "callback", "successCallback", "errorCallback", "failureCallback"]);
+
   switch (iterator) {
     case "sync":
       return emitES6DomIterators();
@@ -685,6 +687,7 @@
       const isOptional = !p.variadic && p.optional;
       const variadicParams = p.variadic && pType.indexOf("|") !== -1;
       return (
+        (deferredParameterNames.has(p.name) ? "/** @deferred */ ": "") +
         (p.variadic ? "..." : "") +
         adjustParamName(p.name) +
         (isOptional ? "?: " : ": ") +
@@ -1068,12 +1071,12 @@
 
         if (i.name === "EventSource") {
           printer.printLine(
-            `${fPrefix}${addOrRemove}EventListener(type: string, listener: (this: EventSource, event: MessageEvent) => any, options?: boolean | ${optionsType}): void;`,
+            `${fPrefix}${addOrRemove}EventListener(type: string, /** @deferred */ listener: (this: EventSource, event: MessageEvent) => any, options?: boolean | ${optionsType}): void;`,
           );
         }
 
         printer.printLine(
-          `${fPrefix}${addOrRemove}EventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | ${optionsType}): void;`,
+          `${fPrefix}${addOrRemove}EventListener(type: string, /** @deferred */ listener: EventListenerOrEventListenerObject, options?: boolean | ${optionsType}): void;`,
         );
       }
     }
@@ -1089,7 +1092,7 @@
       printer.printLine(
         `${prefix}${addOrRemove}EventListener<K extends keyof ${
           iParent.name
-        }EventMap>(type: K, listener: (this: ${nameWithForwardedTypes(
+        }EventMap>(type: K, /** @deferred */ listener: (this: ${nameWithForwardedTypes(
           i,
         )}, ev: ${
           iParent.name