[FIR2IR] Minor. Cleanup Fir2IrVisitor.convertToIrReceiverExpression

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrVisitor.kt

@@ -937,12 +937,16 @@ class Fir2IrVisitor(
         selector: FirQualifiedAccessExpression,
     ): IrExpression? {
         val selectorCalleeReference = selector.calleeReference
-        return when (receiver) {
+        val irReceiver = when (receiver) {
             null -> return null
             is FirResolvedQualifier -> callGenerator.convertToGetObject(receiver, selector as? FirCallableReferenceAccess)
-            is FirFunctionCall, is FirThisReceiverExpression, is FirCallableReferenceAccess, is FirSmartCastExpression ->
+            is FirFunctionCall,
-                convertToIrExpression(receiver)
+            is FirThisReceiverExpression,
-            else -> if (receiver is FirQualifiedAccessExpression && receiver.explicitReceiver == null) {
+            is FirCallableReferenceAccess,
+            is FirSmartCastExpression -> convertToIrExpression(receiver)
+
+            is FirQualifiedAccessExpression -> when (receiver.explicitReceiver) {
+                null -> {
                     val variableAsFunctionMode = selectorCalleeReference is FirResolvedNamedReference &&
                             selectorCalleeReference.name != OperatorNameConventions.INVOKE &&
                             (selectorCalleeReference.resolvedSymbol as? FirCallableSymbol)?.callableId?.callableName == OperatorNameConventions.INVOKE
@@ -950,18 +954,19 @@ class Fir2IrVisitor(
                         receiver, receiver.resolvedType, explicitReceiverExpression = null,
                         variableAsFunctionMode = variableAsFunctionMode
                     )
-            } else {
-                convertToIrExpression(receiver)
                 }
-        }?.run {
+                else -> convertToIrExpression(receiver)
-            if (receiver is FirQualifiedAccessExpression && receiver.calleeReference is FirSuperReference) return@run this
+            }
+            else -> convertToIrExpression(receiver)
+        } ?: return null
 
-            implicitCastInserter.implicitCastFromReceivers(
+        if (receiver is FirQualifiedAccessExpression && receiver.calleeReference is FirSuperReference) return irReceiver
-                this, receiver, selector,
+
+        return implicitCastInserter.implicitCastFromReceivers(
+            irReceiver, receiver, selector,
             conversionScope.defaultConversionTypeOrigin()
         )
     }
-    }
 
     private fun List<FirStatement>.mapToIrStatements(recognizePostfixIncDec: Boolean = true): List<IrStatement?> {
         var index = 0