Ignore deserialized fake-override fields

Fix #1748

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/irasdescriptors/NewIrUtils.kt

@@ -93,6 +93,7 @@ fun IrClass.getSuperInterfaces() = this.superClasses.map { it.owner }.filter { i
 
 val IrProperty.konanBackingField: IrField?
     get() {
+        assert(this.isReal)
         this.backingField?.let { return it }
 
         (this.descriptor as? DeserializedPropertyDescriptor)?.backingField?.let { backingFieldDescriptor ->
@@ -116,6 +117,10 @@ val IrField.containingClass get() = this.parent as? IrClass
 
 val IrFunction.isReal get() = this.origin != IrDeclarationOrigin.FAKE_OVERRIDE
 
+// Note: psi2ir doesn't set `origin = FAKE_OVERRIDE` for fields and properties yet.
+val IrProperty.isReal: Boolean get() = this.descriptor.kind.isReal
+val IrField.isReal: Boolean get() = this.descriptor.kind.isReal
+
 val IrSimpleFunction.isOverridable: Boolean
     get() = visibility != Visibilities.PRIVATE
             && modality != Modality.FINAL

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/LlvmDeclarations.kt

@@ -127,8 +127,8 @@ private fun Context.getDeclaredFields(classDescriptor: ClassDescriptor): List<Ir
     val irClass = classDescriptor
     val fields = irClass.declarations.mapNotNull {
         when (it) {
-            is IrField -> it
-            is IrProperty -> it.konanBackingField
+            is IrField -> it.takeIf { it.isReal }
+            is IrProperty -> it.takeIf { it.isReal }?.konanBackingField
             else -> null
         }
     }