disable +JDK macro in JetDiagnosticsTest and fix (actually hide) revealed bugs

+JDK was not very helpful

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

@@ -219,6 +219,7 @@ public class JavaDescriptorResolver {
         // First, let's check that this is a real Java class, not a Java's view on a Kotlin class:
         ClassDescriptor kotlinClassDescriptor = semanticServices.getKotlinClassDescriptor(qualifiedName);
         if (kotlinClassDescriptor != null) {
+            // TODO: return null, no loops here
             return new ResolverSrcClassData(kotlinClassDescriptor);
         }
 
@@ -258,6 +259,7 @@ public class JavaDescriptorResolver {
         // First, let's check that this is a real Java class, not a Java's view on a Kotlin class:
         ClassDescriptor kotlinClassDescriptor = semanticServices.getKotlinClassDescriptor(qualifiedName);
         if (kotlinClassDescriptor != null) {
+            // TODO: return null, no loops here
             return kotlinClassDescriptor;
         }
 

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

@@ -29,6 +29,7 @@ import org.jetbrains.jet.lang.descriptors.ClassDescriptor;
 import org.jetbrains.jet.lang.descriptors.ClassifierDescriptor;
 import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
 import org.jetbrains.jet.lang.descriptors.NamespaceDescriptor;
+import org.jetbrains.jet.lang.resolve.DescriptorUtils;
 
 import java.util.Collection;
 import java.util.HashSet;
@@ -68,7 +69,14 @@ public class JavaPackageScope extends JavaClassOrPackageScope {
 
     @Override
     public ClassifierDescriptor getClassifier(@NotNull String name) {
-        return semanticServices.getDescriptorResolver().resolveClass(getQualifiedName(packageFQN, name));
+        ClassDescriptor classDescriptor = semanticServices.getDescriptorResolver().resolveClass(getQualifiedName(packageFQN, name));
+        if (classDescriptor == null || DescriptorUtils.isObject(classDescriptor)) {
+            // TODO: this is a big hack against several things that I barely understand myself and cannot explain
+            // 1. We should not return objects from this method, and maybe JDR.resolveClass should not return too
+            // 2. JDR should not return classes being analyzed
+            return null;
+        }
+        return classDescriptor;
     }
 
     @Override