Rename ClassKind.isObject -> isSingleton

"isObject" gives a false impression that this is a check if the kind is OBJECT

compiler/tests/org/jetbrains/jet/descriptors/serialization/AbstractDescriptorSerializationTest.java

@@ -30,11 +30,11 @@ import org.jetbrains.jet.lang.resolve.DescriptorUtils;
 import org.jetbrains.jet.lang.resolve.java.JavaDescriptorResolver;
 import org.jetbrains.jet.lang.resolve.lazy.KotlinTestWithEnvironment;
 import org.jetbrains.jet.lang.resolve.lazy.LazyResolveTestUtil;
-import org.jetbrains.jet.storage.LockBasedStorageManager;
 import org.jetbrains.jet.lang.resolve.name.FqName;
 import org.jetbrains.jet.lang.resolve.name.Name;
 import org.jetbrains.jet.lang.resolve.scopes.JetScope;
 import org.jetbrains.jet.lang.resolve.scopes.WritableScope;
+import org.jetbrains.jet.storage.LockBasedStorageManager;
 import org.jetbrains.jet.test.util.NamespaceComparator;
 
 import java.io.File;
@@ -98,7 +98,7 @@ public abstract class AbstractDescriptorSerializationTest extends KotlinTestWith
             ClassId classId = getClassId(classDescriptor);
             ClassDescriptor descriptor = descriptorFinder.findClass(classId);
             assert descriptor != null : "Class not loaded: " + classId;
-            if (descriptor.getKind().isObject()) {
+            if (descriptor.getKind().isSingleton()) {
                 namespace.getMemberScope().addObjectDescriptor(descriptor);
             }
             else {

compiler/tests/org/jetbrains/jet/test/util/DescriptorValidator.java

@@ -396,7 +396,7 @@ public class DescriptorValidator {
         public Void visitClassDescriptor(
                 ClassDescriptor descriptor, JetScope scope
         ) {
-            if (descriptor.getKind().isObject()) {
+            if (descriptor.getKind().isSingleton()) {
                 assertFound(scope, descriptor, scope.getObjectDescriptor(descriptor.getName()));
             }
             else {