Fixed WrappedClassDescriptor

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/descriptors/WrappedDescriptors.kt

diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/descriptors/WrappedDescriptors.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/descriptors/WrappedDescriptors.kt
index 9df7a93..a25892e 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/descriptors/WrappedDescriptors.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/descriptors/WrappedDescriptors.kt
@@ -491,9 +491,8 @@
 
     override fun getThisAsReceiverParameter() = owner.thisReceiver?.descriptor as ReceiverParameterDescriptor
 
-    override fun getUnsubstitutedPrimaryConstructor(): ClassConstructorDescriptor? {
-        TODO("not implemented")
-    }
+    override fun getUnsubstitutedPrimaryConstructor() =
+        owner.declarations.filterIsInstance<IrConstructor>().singleOrNull { it.isPrimary }?.descriptor
 
     override fun getDeclaredTypeParameters() = owner.typeParameters.map { it.descriptor }