LibJS: Convert internal_get_prototype_of() to ThrowCompletionOr

Author: https://github.com/linusg
Commit: 5148150e1c
Pull-request: https://github.com/SerenityOS/serenity/pull/10266
Reviewed-by: https://github.com/IdanHo ✅

Userland/Libraries/LibJS/Runtime/ProxyObject.h

@@ -7,6 +7,7 @@
 
 #pragma once
 
+#include <LibJS/Runtime/Completion.h>
 #include <LibJS/Runtime/FunctionObject.h>
 
 namespace JS {
@@ -34,7 +35,7 @@ public:
 
     // 10.5 Proxy Object Internal Methods and Internal Slots, https://tc39.es/ecma262/#sec-proxy-object-internal-methods-and-internal-slots
 
-    virtual Object* internal_get_prototype_of() const override;
+    virtual ThrowCompletionOr<Object*> internal_get_prototype_of() const override;
     virtual bool internal_set_prototype_of(Object* prototype) override;
     virtual bool internal_is_extensible() const override;
     virtual bool internal_prevent_extensions() override;