Add a type method to ScriptFetcher

This is to enable checking ScriptFetcher type without RTTI.

Author: heimskr

Source/JavaScriptCore/runtime/ScriptFetcher.h

@@ -31,7 +31,17 @@ namespace JSC {
 
 class ScriptFetcher : public RefCounted<ScriptFetcher> {
 public:
-    virtual ~ScriptFetcher() { }
+    enum class Type: uint8_t {
+        Cached,
+        Worker,
+#if USE(BUN_JSC_ADDITIONS)
+        NodeVM,
+#endif
+    };
+
+    virtual ~ScriptFetcher() = default;
+
+    virtual Type type() const = 0;
 };
 
 } // namespace JSC

Source/WebCore/bindings/js/CachedScriptFetcher.h

@@ -44,6 +44,8 @@ class CachedScriptFetcher : public JSC::ScriptFetcher {
 
     static Ref<CachedScriptFetcher> create(const AtomString& charset);
 
+    Type type() const final { return Type::Cached; }
+
 protected:
     CachedScriptFetcher(const String& nonce, ReferrerPolicy referrerPolicy, RequestPriority fetchPriority, const AtomString& charset, const AtomString& initiatorType, bool isInUserAgentShadowTree)
         : m_nonce(nonce)

Source/WebCore/bindings/js/WorkerScriptFetcher.h

@@ -44,6 +44,8 @@ class WorkerScriptFetcher final : public JSC::ScriptFetcher {
         return adoptRef(*new WorkerScriptFetcher(WTFMove(parameters), credentials, destination, referrerPolicy));
     }
 
+    Type type() const final { return Type::Worker; }
+
     FetchOptions::Credentials credentials() const { return m_credentials; }
     FetchOptions::Destination destination() const { return m_destination; }
     ReferrerPolicy referrerPolicy() const { return m_referrerPolicy; }