handle interface forwarding

Author: Renegade334

baselines/dom.generated.d.ts

@@ -7466,7 +7466,6 @@ interface CSSStyleProperties extends CSSStyleDeclarationBase {
     zIndex: string;
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/CSS/zoom) */
     zoom: string;
-    readonly [Symbol.toStringTag]: "CSSStyleProperties";
 }
 
 declare var CSSStyleProperties: {

src/build/emitter.ts

@@ -197,14 +197,16 @@ export function emitWebIdl(
     (i) => getExtendList(i.name).concat(getImplementList(i.name)),
   );
 
-  /// Reverse map of interfaces to those that inherit from it
-  /// e.g. If i1 depends on i2, i1 should be in childrenMap.[i2.Name]
-  const iNameToIChildrenList = allNonCallbackInterfaces.reduce(
-    (result, i): Record<string, string[]> => {
-      result[i.name] ??= [];
+  /// Interface name mapped to whether that interface is an inheritance target
+  const iNameIsInheritanceTarget = allNonCallbackInterfaces.reduce(
+    (result, i): Record<string, boolean> => {
+      result[i.name] ??= false;
+      if (i.forwardExtends) {
+        result[i.forwardExtends] = true;
+      }
       iNameToIDependList[i.name].forEach((name) => {
         name = name.replace(/<.*>$/, "");
-        (result[name] ??= []).push(i.name);
+        result[name] = true;
       });
       return result;
     },
@@ -1526,6 +1528,7 @@ export function emitWebIdl(
         name: i.name,
         extends: i.forwardExtends,
         constructor: undefined,
+        noToStringTag: true,
       });
     }
 
@@ -1653,7 +1656,7 @@ export function emitWebIdl(
       return;
     }
     // Do not emit toString tag if interface is an inheritance target of other interfaces
-    if (iNameToIChildrenList[i.name].length) {
+    if (iNameIsInheritanceTarget[i.name]) {
       return;
     }
     printer.printLine(