Fix microsoft/TypeScript#18073

Author: mhegazy

baselines/dom.generated.d.ts

@@ -3885,7 +3885,7 @@ interface Headers {
 
 declare var Headers: {
     prototype: Headers;
-    new(init?: Headers | string[][]): Headers;
+    new (init?: Headers | string[][] | object): Headers;;
 };
 
 interface History {
@@ -14842,4 +14842,4 @@ type ServiceWorkerState = "installing" | "installed" | "activating" | "activated
 type Transport = "usb" | "nfc" | "ble";
 type VideoFacingModeEnum = "user" | "environment" | "left" | "right";
 type VisibilityState = "hidden" | "visible" | "prerender" | "unloaded";
-type XMLHttpRequestResponseType = "" | "arraybuffer" | "blob" | "document" | "json" | "text";
+type XMLHttpRequestResponseType = "" | "arraybuffer" | "blob" | "document" | "json" | "text";

baselines/webworker.generated.d.ts

@@ -470,7 +470,7 @@ interface Headers {
 
 declare var Headers: {
     prototype: Headers;
-    new(init?: Headers | string[][]): Headers;
+    new (init?: Headers | string[][] | object): Headers;;
 };
 
 interface IDBCursor {

inputfiles/overridingTypes.json

@@ -1376,5 +1376,12 @@
         "readonly": true,
         "name": "form",
         "type": "HTMLFormElement | null"
+    },
+    {
+        "kind": "constructor",
+        "interface": "Headers",
+        "signatures": [
+            "new (init?: Headers | string[][] | object): Headers;"
+        ]
     }
  ]