IR: generate lambdas in place in Psi2Ir

even when arguments are to be rearranged.
Lambdas have no side effects, and storing them in temporary variables
prevents processing in the backend
(such as inserting continuation parameter in AddContinuationLowering).

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

@@ -384,7 +384,10 @@ class CallGenerator(statementGenerator: StatementGenerator) : StatementGenerator
         for (valueArgument in valueArgumentsInEvaluationOrder) {
             val valueParameter = valueArgumentsToValueParameters[valueArgument]!!
             val irArgument = call.getValueArgument(valueParameter) ?: continue
-            val irArgumentValue = scope.createTemporaryVariableInBlock(context, irArgument, irBlock, valueParameter.name.asString())
+            val irArgumentValue = if (irArgument.hasNoSideEffects())
+                generateExpressionValue(irArgument.type) { irArgument }    // Computing a lambda has no side effects, can generate in place
+            else
+                scope.createTemporaryVariableInBlock(context, irArgument, irBlock, valueParameter.name.asString())
             irArgumentValues[valueParameter] = irArgumentValue
         }
 
@@ -399,6 +402,12 @@ class CallGenerator(statementGenerator: StatementGenerator) : StatementGenerator
     }
 }
 
+fun IrExpression.hasNoSideEffects() =
+    this is IrFunctionExpression ||
+            (this is IrCallableReference && dispatchReceiver == null && extensionReceiver == null) ||
+            this is IrClassReference ||
+            this is IrConst<*>
+
 fun CallGenerator.generateCall(ktElement: KtElement, call: CallBuilder, origin: IrStatementOrigin? = null) =
     generateCall(ktElement.startOffsetSkippingComments, ktElement.endOffset, call, origin)