JVM IR: fix noarg plugin for sealed class with existing noarg ctor

#KT-48111 Fixed

plugins/noarg/noarg-cli/testData/box/sealedClassWithExistingNoargCtor.kt

@@ -0,0 +1,14 @@
+// WITH_RUNTIME
+
+annotation class NoArg
+
+@NoArg
+sealed class MappedSuperClass
+
+@NoArg
+class ConcreteClass(val x: String) : MappedSuperClass()
+
+fun box(): String {
+    ConcreteClass::class.java.getConstructor().newInstance()
+    return "OK"
+}