Do not consider 'expect' class type constructors final

Because even a final expected class can be actualized with an open
actual class and thus have subtypes in the platform code

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/lazy/descriptors/LazyJavaClassDescriptor.kt

@@ -255,8 +255,6 @@ class LazyJavaClassDescriptor(
         override val supertypeLoopChecker: SupertypeLoopChecker
             get() = c.components.supertypeLoopChecker
 
-        override fun isFinal(): Boolean = isFinalClass
-
         override fun isDenotable(): Boolean = true
 
         override fun getDeclarationDescriptor(): ClassDescriptor = this@LazyJavaClassDescriptor

core/descriptors/src/org/jetbrains/kotlin/builtins/functions/FunctionClassDescriptor.kt

@@ -152,7 +152,6 @@ class FunctionClassDescriptor(
 
         override fun getDeclarationDescriptor() = this@FunctionClassDescriptor
         override fun isDenotable() = true
-        override fun isFinal() = false
 
         override fun toString() = declarationDescriptor.toString()
 

core/descriptors/src/org/jetbrains/kotlin/types/AbstractClassTypeConstructor.java

@@ -53,6 +53,12 @@ public abstract class AbstractClassTypeConstructor extends AbstractTypeConstruct
     @Override
     public abstract ClassDescriptor getDeclarationDescriptor();
 
+    @Override
+    public final boolean isFinal() {
+        ClassDescriptor descriptor = getDeclarationDescriptor();
+        return descriptor.getModality() == Modality.FINAL && !descriptor.isExpect();
+    }
+
     @NotNull
     @Override
     public KotlinBuiltIns getBuiltIns() {

core/descriptors/src/org/jetbrains/kotlin/types/ClassTypeConstructorImpl.java

@@ -18,7 +18,6 @@ package org.jetbrains.kotlin.types;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.kotlin.descriptors.ClassDescriptor;
-import org.jetbrains.kotlin.descriptors.Modality;
 import org.jetbrains.kotlin.descriptors.SupertypeLoopChecker;
 import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor;
 import org.jetbrains.kotlin.resolve.DescriptorUtils;
@@ -56,11 +55,6 @@ public class ClassTypeConstructorImpl extends AbstractClassTypeConstructor imple
         return DescriptorUtils.getFqName(classDescriptor).asString();
     }
 
-    @Override
-    public boolean isFinal() {
-        return classDescriptor.getModality() == Modality.FINAL;
-    }
-
     @Override
     public boolean isDenotable() {
         return true;

core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/descriptors/DeserializedClassDescriptor.kt

@@ -195,8 +195,6 @@ class DeserializedClassDescriptor(
 
         override fun getParameters() = parameters()
 
-        override fun isFinal(): Boolean = isFinalClass
-
         override fun isDenotable() = true
 
         override fun getDeclarationDescriptor() = this@DeserializedClassDescriptor