Minor: simplify OperatorExpressionGenerator#invokeConversionFunction

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

@@ -31,9 +31,6 @@ import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
 import org.jetbrains.kotlin.psi.psiUtil.startOffset
 import org.jetbrains.kotlin.psi2ir.findSingleFunction
-import org.jetbrains.kotlin.psi2ir.intermediate.CallReceiver
-import org.jetbrains.kotlin.psi2ir.intermediate.OnceExpressionValue
-import org.jetbrains.kotlin.psi2ir.intermediate.SimpleCallReceiver
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
 import org.jetbrains.kotlin.resolve.constants.evaluate.ConstantExpressionEvaluator
@@ -257,20 +254,20 @@ class OperatorExpressionGenerator(statementGenerator: StatementGenerator) : Stat
                 this
 
             else ->
-                SimpleCallReceiver(OnceExpressionValue(this), null)
+                invokeConversionFunction(
-                    .invokeConversionFunction(
                     startOffset, endOffset,
-                        conversionFunction ?: throw AssertionError("No conversion function for $type ~> $targetType")
+                    conversionFunction ?: throw AssertionError("No conversion function for $type ~> $targetType"),
+                    this
                 )
         }
     }
 
-    private fun CallReceiver.invokeConversionFunction(
+    private fun invokeConversionFunction(
         startOffset: Int,
         endOffset: Int,
-        functionDescriptor: FunctionDescriptor
+        functionDescriptor: FunctionDescriptor,
+        receiver: IrExpression
     ): IrExpression =
-        call { dispatchReceiverValue, _ ->
         IrCallImpl(
             startOffset,
             endOffset,
@@ -281,8 +278,7 @@ class OperatorExpressionGenerator(statementGenerator: StatementGenerator) : Stat
             origin = null, // TODO origin for widening conversions?
             superQualifierSymbol = null
         ).apply {
-                dispatchReceiver = dispatchReceiverValue!!.load()
+            dispatchReceiver = receiver
-            }
         }
 
     private fun KotlinType.findConversionFunctionTo(targetType: KotlinType): FunctionDescriptor? {