maintain static fields in runtime

runtime.js

@@ -4,8 +4,9 @@
 'use strict';
 
 function Runtime() {
-  this.initialized = Object.create(null);
-  this.pending = Object.create(null);
+  this.initialized = {};
+  this.pending = {};
+  this.staticFields = {};
 }
 
 Runtime.prototype.newPrimitiveArray = function(type, size) {

vm.js

@@ -879,7 +879,7 @@ VM.execute = function(ctx) {
                 field = resolve(op, idx);
                 classInitCheck(field.classInfo, frame.ip-3);
             }
-            var value = field.value;
+            var value = ctx.runtime.staticFields[field.id];
             if (typeof value === "undefined") {
                 value = util.defaultValue(field.signature);
             }
@@ -892,7 +892,7 @@ VM.execute = function(ctx) {
                 field = resolve(op, idx);
                 classInitCheck(field.classInfo, frame.ip-3);
             }
-            field.value = stack.popType(field.signature);
+            ctx.runtime.staticFields[field.id] = stack.popType(field.signature);
             break;
         case 0xbb: // new
             var idx = frame.read16();