Fix type of IllegalArgumentException call for illegal step in StepHandler.

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/loops/HeaderProcessor.kt

@@ -329,15 +329,18 @@ internal class HeaderProcessor(
                 )
             } else null
 
-            val stepVariable = scope.createTemporaryVariable(
-                ensureNotNullable(
-                    headerInfo.step.castIfNecessary(
-                        headerInfo.progressionType.stepType(context.irBuiltIns),
-                        headerInfo.progressionType.stepCastFunctionName
-                    )
-                ),
-                nameHint = "step"
-            )
+            val stepVariable = headerInfo.progressionType.stepType(context.irBuiltIns).let {
+                scope.createTemporaryVariable(
+                    ensureNotNullable(
+                        headerInfo.step.castIfNecessary(
+                            it,
+                            headerInfo.progressionType.stepCastFunctionName
+                        )
+                    ),
+                    nameHint = "step",
+                    irType = it
+                )
+            }
 
             return when (headerInfo) {
                 is IndexedGetHeaderInfo -> IndexedGetLoopHeader(

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/loops/ProgressionHandlers.kt

@@ -261,7 +261,7 @@ internal class StepHandler(
             val stepGreaterFun = context.irBuiltIns.greaterFunByOperandType[stepType.toKotlinType()]!!
             val zeroStep = if (data == ProgressionType.LONG_PROGRESSION) irLong(0) else irInt(0)
             val throwIllegalStepExceptionCall = {
-                irCall(context.irBuiltIns.illegalArgumentExceptionSymbol, stepType).apply {
+                irCall(context.irBuiltIns.illegalArgumentExceptionSymbol).apply {
                     val exceptionMessage = irConcat()
                     exceptionMessage.addArgument(irString("Step must be positive, was: "))
                     exceptionMessage.addArgument(stepArgExpression.deepCopyWithSymbols())

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/loops/Utils.kt

@@ -15,16 +15,18 @@ import org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrConstImpl
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.getClass
+import org.jetbrains.kotlin.ir.types.isNothing
 import org.jetbrains.kotlin.ir.util.functions
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.util.OperatorNameConventions
 
 internal fun IrExpression.castIfNecessary(targetType: IrType, numberCastFunctionName: Name): IrExpression {
-    return if (type == targetType) {
+    // This expression's type could be Nothing from an exception throw.
+    return if (type == targetType || type.isNothing()) {
         this
     } else {
-        val function = type.getClass()!!.functions.first { it.name == numberCastFunctionName }
-        IrCallImpl(startOffset, endOffset, function.returnType, function.symbol)
+        val castFun = type.getClass()!!.functions.first { it.name == numberCastFunctionName }
+        IrCallImpl(startOffset, endOffset, castFun.returnType, castFun.symbol)
             .apply { dispatchReceiver = this@castIfNecessary }
     }
 }
@@ -35,6 +37,9 @@ internal fun IrExpression.negate(): IrExpression {
         is Int -> IrConstImpl(startOffset, endOffset, type, IrConstKind.Int, -value)
         is Long -> IrConstImpl(startOffset, endOffset, type, IrConstKind.Long, -value)
         else -> {
+            // This expression's type could be Nothing from an exception throw, in which case the unary minus function will not exist.
+            if (type.isNothing()) return this
+
             val unaryMinusFun = type.getClass()!!.functions.first { it.name == OperatorNameConventions.UNARY_MINUS }
             IrCallImpl(startOffset, endOffset, type, unaryMinusFun.symbol, unaryMinusFun.descriptor).apply {
                 dispatchReceiver = this@negate