LibJS: Add Object::put_native_function() for convenience

This makes it a little bit nicer to add native function properties
to JavaScript objects.

Thanks to Sergey for suggesting it! :^)

Libraries/LibJS/GlobalObject.cpp

@@ -9,18 +9,18 @@
 
 namespace JS {
 
-GlobalObject::GlobalObject(Heap& heap)
+GlobalObject::GlobalObject()
 {
-    put("print", heap.allocate<NativeFunction>([](Interpreter&, Vector<Value> arguments) -> Value {
+    put_native_function("print", [](Interpreter&, Vector<Value> arguments) -> Value {
         for (auto& argument : arguments)
             printf("%s ", argument.to_string().characters());
         return js_undefined();
-    }));
+    });
-    put("gc", heap.allocate<NativeFunction>([](Interpreter& interpreter, Vector<Value>) -> Value {
+    put_native_function("gc", [](Interpreter& interpreter, Vector<Value>) -> Value {
         dbg() << "Forced garbage collection requested!";
         interpreter.heap().collect_garbage();
         return js_undefined();
-    }));
+    });
 }
 
 GlobalObject::~GlobalObject()

Libraries/LibJS/GlobalObject.h

@@ -6,7 +6,7 @@ namespace JS {
 
 class GlobalObject final : public Object {
 public:
-    explicit GlobalObject(Heap&);
+    explicit GlobalObject();
     virtual ~GlobalObject() override;
 
 private:

Libraries/LibJS/Interpreter.cpp

@@ -37,7 +37,7 @@ namespace JS {
 Interpreter::Interpreter()
     : m_heap(*this)
 {
-    m_global_object = heap().allocate<GlobalObject>(heap());
+    m_global_object = heap().allocate<GlobalObject>();
 }
 
 Interpreter::~Interpreter()

Libraries/LibJS/Object.cpp

@@ -25,6 +25,8 @@
  */
 
 #include <AK/String.h>
+#include <LibJS/Heap.h>
+#include <LibJS/NativeFunction.h>
 #include <LibJS/Object.h>
 #include <LibJS/Value.h>
 
@@ -48,6 +50,11 @@ void Object::put(String property_name, Value value)
     m_properties.set(property_name, move(value));
 }
 
+void Object::put_native_function(String property_name, AK::Function<Value(Interpreter&, Vector<Value>)> native_function)
+{
+    put(property_name, heap().allocate<NativeFunction>(move(native_function)));
+}
+
 void Object::visit_children(Cell::Visitor& visitor)
 {
     Cell::visit_children(visitor);

Libraries/LibJS/Object.h

@@ -41,6 +41,8 @@ public:
     Value get(String property_name) const;
     void put(String property_name, Value);
 
+    void put_native_function(String property_name, AK::Function<Value(Interpreter&, Vector<Value>)>);
+
     virtual bool is_function() const { return false; }
     virtual bool is_native_function() const { return false; }