Convert NativeObject from IdScriptableObject to lambda constructor

* Make built-in function source spec compliant.
* Pull JS methods out into separate private methods.
* Refactor away from `IdFunctionObject`s.
* Conversion of `NativeObject` to `LambdaConstructor`.
* Update Test262 test properties.
* Seal Object prototype when sealing constructor.
* Recover performance in nsieve benchmark.
* Refactor method declarations for readability.

Author: aardvark179

rhino/src/main/java/org/mozilla/javascript/BaseFunction.java

@@ -391,7 +391,8 @@ public Object execIdCall(
                                 ((NativeFunction) ((BoundFunction) thisObj).getTargetFunction())
                                         .getPrototypeProperty();
                     else protoProp = ScriptableObject.getProperty(thisObj, "prototype");
-                    if (protoProp instanceof IdScriptableObject) {
+                    if (protoProp instanceof NativeObject
+                            || protoProp instanceof IdScriptableObject) {
                         return ScriptRuntime.jsDelegatesTo(obj, (Scriptable) protoProp);
                     }
                     throw ScriptRuntime.typeErrorById(
@@ -505,9 +506,7 @@ String decompile(int indent, EnumSet<DecompilerFlag> flags) {
             sb.append(getFunctionName());
             sb.append("() {\n\t");
         }
-        sb.append("[native code, arity=");
-        sb.append(getArity());
-        sb.append("]\n");
+        sb.append("[native code]\n");
         if (!justbody) {
             sb.append("}\n");
         }

rhino/src/main/java/org/mozilla/javascript/ES6Iterator.java

@@ -42,8 +42,7 @@ protected ES6Iterator(Scriptable scope, String tag) {
         this.tag = tag;
         Scriptable top = ScriptableObject.getTopLevelScope(scope);
         this.setParentScope(top);
-        IdScriptableObject prototype =
-                (IdScriptableObject) ScriptableObject.getTopScopeValue(top, tag);
+        ScriptableObject prototype = (ScriptableObject) ScriptableObject.getTopScopeValue(top, tag);
         setPrototype(prototype);
     }
 

rhino/src/main/java/org/mozilla/javascript/EmbeddedSlotMap.java

@@ -26,6 +26,7 @@ public class EmbeddedSlotMap implements SlotMap {
     private Slot lastAdded;
 
     private int count;
+    private boolean hasIndex = false;
 
     // initial slot array size, must be a power of 2
     private static final int INITIAL_SLOT_SIZE = 4;
@@ -79,7 +80,7 @@ public Iterator<Slot> iterator() {
     /** Locate the slot with the given name or index. */
     @Override
     public Slot query(Object key, int index) {
-        if (slots == null) {
+        if (slots == null || (key == null && !hasIndex)) {
             return null;
         }
 
@@ -231,6 +232,7 @@ private void insertNewSlot(Slot newSlot) {
             firstAdded = newSlot;
         }
         lastAdded = newSlot;
+        if (newSlot.name == null) hasIndex = true;
         addKnownAbsentSlot(slots, newSlot);
     }
 

rhino/src/main/java/org/mozilla/javascript/IdFunctionObject.java

@@ -8,8 +8,6 @@
 
 package org.mozilla.javascript;
 
-import java.util.EnumSet;
-
 public class IdFunctionObject extends BaseFunction {
     private static final long serialVersionUID = -5332312783643935019L;
 
@@ -97,28 +95,6 @@ public Scriptable createObject(Context cx, Scriptable scope) {
         throw ScriptRuntime.typeErrorById("msg.not.ctor", functionName);
     }
 
-    @Override
-    String decompile(int indent, EnumSet<DecompilerFlag> flags) {
-        StringBuilder sb = new StringBuilder();
-        boolean justbody = flags.contains(DecompilerFlag.ONLY_BODY);
-        if (!justbody) {
-            sb.append("function ");
-            sb.append(getFunctionName());
-            sb.append("() { ");
-        }
-        sb.append("[native code for ");
-        if (idcall instanceof Scriptable) {
-            Scriptable sobj = (Scriptable) idcall;
-            sb.append(sobj.getClassName());
-            sb.append('.');
-        }
-        sb.append(getFunctionName());
-        sb.append(", arity=");
-        sb.append(getArity());
-        sb.append(justbody ? "]\n" : "] }\n");
-        return sb.toString();
-    }
-
     @Override
     public int getArity() {
         return arity;

rhino/src/main/java/org/mozilla/javascript/LambdaConstructor.java

@@ -181,6 +181,24 @@ public void definePrototypeMethod(
         proto.defineProperty(name, f, attributes);
     }
 
+    /**
+     * Define a function property on the prototype of the constructor using a LambdaFunction under
+     * the covers.
+     */
+    public void definePrototypeMethod(
+            Scriptable scope,
+            String name,
+            int length,
+            Object prototype,
+            SerializableCallable target,
+            int attributes,
+            int propertyAttributes) {
+        LambdaFunction f = new LambdaFunction(scope, name, length, prototype, target);
+        f.setStandardPropertyAttributes(propertyAttributes);
+        ScriptableObject proto = getPrototypeScriptable();
+        proto.defineProperty(name, f, attributes);
+    }
+
     /** Define a property that may be of any type on the prototype of this constructor. */
     public void definePrototypeProperty(String name, Object value, int attributes) {
         ScriptableObject proto = getPrototypeScriptable();
@@ -306,6 +324,24 @@ public void defineConstructorMethod(
         defineProperty(name, f, attributes);
     }
 
+    /**
+     * Define a function property directly on the constructor that is implemented under the covers
+     * by a LambdaFunction, and override the properties of its "name", "length", "arity", and
+     * "protoyupe" properties.
+     */
+    public void defineConstructorMethod(
+            Scriptable scope,
+            String name,
+            int length,
+            Object prototype,
+            SerializableCallable target,
+            int attributes,
+            int propertyAttributes) {
+        LambdaFunction f = new LambdaFunction(scope, name, length, prototype, target);
+        f.setStandardPropertyAttributes(propertyAttributes);
+        defineProperty(name, f, attributes);
+    }
+
     /**
      * Replace the default "Object" prototype with a prototype of a specific implementation. This is
      * only necessary for a few built-in constructors, like Boolean, that must have their prototype

rhino/src/main/java/org/mozilla/javascript/LambdaFunction.java

@@ -38,6 +38,30 @@ public LambdaFunction(Scriptable scope, String name, int length, SerializableCal
         setupDefaultPrototype();
     }
 
+    /**
+     * Create a new function. The new object will have the Function prototype and no parent. The
+     * caller is responsible for binding this object to the appropriate scope.
+     *
+     * @param scope scope of the calling context
+     * @param name name of the function
+     * @param length the arity of the function
+     * @param prototype prototype to set for this function
+     * @param target an object that implements the function in Java. Since Callable is a
+     *     single-function interface this will typically be implemented as a lambda.
+     */
+    public LambdaFunction(
+            Scriptable scope,
+            String name,
+            int length,
+            Object prototype,
+            SerializableCallable target) {
+        this.target = target;
+        this.name = name;
+        this.length = length;
+        ScriptRuntime.setFunctionProtoAndParent(this, Context.getCurrentContext(), scope);
+        setPrototypeProperty(prototype);
+    }
+
     /** Create a new built-in function, with no name, and no default prototype. */
     public LambdaFunction(Scriptable scope, int length, SerializableCallable target) {
         this.target = target;