LibJS: Pass call/construct argument lists as ReadonlySpan<Value>

(Instead of MarkedVector<Value>.) This is a step towards not storing
argument lists in MarkedVector<Value> at all. Note that they still end
up in MarkedVectors since that's what ExecutionContext has.

Userland/Libraries/LibJS/Runtime/Array.cpp

@@ -63,6 +63,24 @@ NonnullGCPtr<Array> Array::create_from(Realm& realm, Vector<Value> const& elemen
     return array;
 }
 
+NonnullGCPtr<Array> Array::create_from(Realm& realm, ReadonlySpan<Value> const& elements)
+{
+    // 1. Let array be ! ArrayCreate(0).
+    auto array = MUST(Array::create(realm, 0));
+
+    // 2. Let n be 0.
+    // 3. For each element e of elements, do
+    for (u32 n = 0; n < elements.size(); ++n) {
+        // a. Perform ! CreateDataPropertyOrThrow(array, ! ToString(𝔽(n)), e).
+        MUST(array->create_data_property_or_throw(n, elements[n]));
+
+        // b. Set n to n + 1.
+    }
+
+    // 4. Return array.
+    return array;
+}
+
 Array::Array(Object& prototype)
     : Object(ConstructWithPrototypeTag::Tag, prototype)
 {