LibJS: Remove Object(Object& prototype) footgun

This constructor was easily confused with a copy constructor, and it was
possible to accidentally copy-construct Objects in at least one way that
we dicovered (via generic ThrowCompletionOr construction).

This patch adds a mandatory ConstructWithPrototypeTag parameter to the
constructor to disambiguate it.

Userland/Libraries/LibJS/Runtime/Promise.cpp

@@ -49,7 +49,7 @@ NonnullGCPtr<Promise> Promise::create(Realm& realm)
 
 // 27.2 Promise Objects, https://tc39.es/ecma262/#sec-promise-objects
 Promise::Promise(Object& prototype)
-    : Object(prototype)
+    : Object(ConstructWithPrototypeTag::Tag, prototype)
 {
 }