PSI2IR Use resulting descriptor extension receiver type

Use resulting descriptor extension receiver type instead of
ReceiverValue.type (which can contain captured types, which would be
approximated, and cause IR validation errors).

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ArgumentsGenerationUtils.kt

@@ -56,7 +56,13 @@ fun StatementGenerator.generateReceiver(ktDefaultElement: KtElement, receiver: R
     generateReceiver(ktDefaultElement.startOffsetSkippingComments, ktDefaultElement.endOffset, receiver)
 
 fun StatementGenerator.generateReceiver(defaultStartOffset: Int, defaultEndOffset: Int, receiver: ReceiverValue): IntermediateValue {
-    val irReceiverType = receiver.type.toIrType()
+    val irReceiverType =
+        when (receiver) {
+            is ExtensionReceiver ->
+                receiver.declarationDescriptor.extensionReceiverParameter!!.type.toIrType()
+            else ->
+                receiver.type.toIrType()
+        }
 
     if (receiver is TransientReceiver) return TransientReceiverValue(irReceiverType)