Realization of class object fields as static fields of outer class

#KT-2213 Fixed

compiler/frontend/src/org/jetbrains/jet/lang/psi/JetPsiUtil.java

@@ -553,6 +553,10 @@ public class JetPsiUtil {
         return getOutermostClassOrObject(classOrObject) == null;
     }
 
+    public static boolean isTrait(@NotNull JetClassOrObject classOrObject) {
+        return classOrObject instanceof JetClass && ((JetClass) classOrObject).isTrait();
+    }
+
     @Nullable
     public static JetClassOrObject getOutermostClassOrObject(@NotNull JetClassOrObject classOrObject) {
         JetClassOrObject current = classOrObject;

compiler/frontend/src/org/jetbrains/jet/lang/resolve/DescriptorUtils.java

@@ -27,6 +27,7 @@ import org.jetbrains.jet.lang.descriptors.impl.AnonymousFunctionDescriptor;
 import org.jetbrains.jet.lang.descriptors.impl.NamespaceDescriptorParent;
 import org.jetbrains.jet.lang.psi.JetElement;
 import org.jetbrains.jet.lang.psi.JetFunction;
+import org.jetbrains.jet.lang.psi.JetProperty;
 import org.jetbrains.jet.lang.resolve.constants.CompileTimeConstant;
 import org.jetbrains.jet.lang.resolve.name.FqName;
 import org.jetbrains.jet.lang.resolve.name.FqNameUnsafe;
@@ -289,6 +290,10 @@ public class DescriptorUtils {
         return isKindOf(descriptor, ClassKind.ENUM_CLASS);
     }
 
+    public static boolean isClass(@NotNull DeclarationDescriptor descriptor) {
+        return isKindOf(descriptor, ClassKind.CLASS);
+    }
+
     public static boolean isKindOf(@NotNull JetType jetType, @NotNull ClassKind classKind) {
         ClassifierDescriptor descriptor = jetType.getConstructor().getDeclarationDescriptor();
         return isKindOf(descriptor, classKind);
@@ -572,4 +577,13 @@ public class DescriptorUtils {
         }
         return allSuperclasses;
     }
+
+    @NotNull
+    public static PropertyDescriptor getPropertyDescriptor(@NotNull JetProperty property, @NotNull BindingContext bindingContext) {
+        VariableDescriptor descriptor = bindingContext.get(BindingContext.VARIABLE, property);
+        if (!(descriptor instanceof PropertyDescriptor)) {
+            throw new UnsupportedOperationException("expect a property to have a property descriptor");
+        }
+        return (PropertyDescriptor) descriptor;
+    }
 }