Add isData() to ClassDescriptor

compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassDescriptor.java

@@ -34,6 +34,7 @@ import org.jetbrains.kotlin.descriptors.*;
 import org.jetbrains.kotlin.descriptors.annotations.Annotations;
 import org.jetbrains.kotlin.descriptors.impl.ClassDescriptorBase;
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation;
+import org.jetbrains.kotlin.lexer.JetTokens;
 import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.psi.*;
 import org.jetbrains.kotlin.resolve.*;
@@ -83,6 +84,7 @@ public class LazyClassDescriptor extends ClassDescriptorBase implements ClassDes
     private final Visibility visibility;
     private final NotNullLazyValue<ClassKind> kind;
     private final NotNullLazyValue<Boolean> isInner;
+    private final NotNullLazyValue<Boolean> isData;
 
     private final Annotations annotations;
     private final Annotations danglingAnnotations;
@@ -153,6 +155,13 @@ public class LazyClassDescriptor extends ClassDescriptorBase implements ClassDes
             }
         });
 
+        this.isData = storageManager.createLazyValue(new Function0<Boolean>() {
+            @Override
+            public Boolean invoke() {
+                return modifierList != null && modifierList.hasModifier(JetTokens.DATA_KEYWORD);
+            }
+        });
+
         this.kind = storageManager.createLazyValue(new Function0<ClassKind>() {
             @Override
             public ClassKind invoke() {
@@ -405,6 +414,11 @@ public class LazyClassDescriptor extends ClassDescriptorBase implements ClassDes
         return isInner.invoke();
     }
 
+    @Override
+    public boolean isData() {
+        return isData.invoke();
+    }
+
     @Override
     public boolean isCompanionObject() {
         return isCompanionObject;