Generate specialized constructor code for constructing simple objects

test/mjsunit/simple-constructor.js

Index: test/mjsunit/simple-constructor.js
===================================================================
--- test/mjsunit/simple-constructor.js	(revision 2762)
+++ test/mjsunit/simple-constructor.js	(working copy)
@@ -53,9 +53,11 @@
 }
 
 o1_1 = new f1();
+assertEquals(1, o1_1.x, "1");
 o1_2 = new f1();
-assertArrayEquals(["x"], props(o1_1));
-assertArrayEquals(["x"], props(o1_2));
+assertEquals(1, o1_1.x, "2");
+assertArrayEquals(["x"], props(o1_1), "3");
+assertArrayEquals(["x"], props(o1_2), "4");
 
 o2_1 = new f2(0);
 o2_2 = new f2(0);
@@ -77,6 +79,49 @@
 assertArrayEquals(["x", "y"], props(o4_1_1));
 assertArrayEquals(["x", "y"], props(o4_1_2));
 
+function f5(x, y) {
+  this.x = x;
+  this.y = y;
+}
+
+function f6(x, y) {
+  this.y = y;
+  this.x = x;
+}
+
+function f7(x, y, z) {
+  this.x = x;
+  this.y = y;
+}
+
+function testArgs(fun) {
+  obj = new fun();
+  assertArrayEquals(["x", "y"], props(obj));
+  assertEquals(void 0, obj.x);
+  assertEquals(void 0, obj.y);
+
+  obj = new fun("x");
+  assertArrayEquals(["x", "y"], props(obj));
+  assertEquals("x", obj.x);
+  assertEquals(void 0, obj.y);
+
+  obj = new fun("x", "y");
+  assertArrayEquals(["x", "y"], props(obj));
+  assertEquals("x", obj.x);
+  assertEquals("y", obj.y);
+
+  obj = new fun("x", "y", "z");
+  assertArrayEquals(["x", "y"], props(obj));
+  assertEquals("x", obj.x);
+  assertEquals("y", obj.y);
+}
+
+for (var i = 0; i < 10; i++) {
+  testArgs(f5);
+  testArgs(f6);
+  testArgs(f7);
+}
+
 function g(){
   this.x=1
 }