JVM_IR: specify correct type for defaultConstructorMarker arguments

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

@@ -368,8 +368,9 @@ open class DefaultParameterInjector(
             )
         }
         if (expression.symbol is IrConstructorSymbol) {
+            val defaultArgumentMarker = context.ir.symbols.defaultConstructorMarker
             params += markerParameterDeclaration(realFunction) to
-                    IrConstImpl.constNull(startOffset, endOffset, context.irBuiltIns.nothingNType)
+                    IrConstImpl.constNull(startOffset, endOffset, defaultArgumentMarker.owner.defaultType.makeNullable())
         } else if (context.ir.shouldGenerateHandlerParameterForDefaultBodyFun()) {
             params += realFunction.valueParameters.last() to
                     IrConstImpl.constNull(startOffset, endOffset, context.irBuiltIns.nothingNType)

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/SyntheticAccessorLowering.kt

@@ -30,6 +30,7 @@ import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.types.classOrNull
 import org.jetbrains.kotlin.ir.types.classifierOrNull
 import org.jetbrains.kotlin.ir.types.isSubtypeOfClass
+import org.jetbrains.kotlin.ir.types.makeNullable
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 import org.jetbrains.kotlin.load.java.JavaVisibilities
@@ -329,7 +330,7 @@ internal class SyntheticAccessorLowering(val context: JvmBackendContext) : IrEle
                 IrConstImpl.constNull(
                     UNDEFINED_OFFSET,
                     UNDEFINED_OFFSET,
-                    context.ir.symbols.defaultConstructorMarker.owner.defaultType
+                    context.ir.symbols.defaultConstructorMarker.owner.defaultType.makeNullable()
                 )
             )
         }

compiler/testData/codegen/bytecodeText/noSuperCheckInDefaultConstuctor.kt

@@ -1,3 +1,4 @@
 class A (i: Int = 0)
 
-// 0 ATHROW
+// 0 ATHROW
+// 0 CHECKCAST