JVM_IR: make constructors of named local classes public

They are accessible through reflection

compiler/testData/writeFlags/function/constructors/localClass.kt

@@ -0,0 +1,9 @@
+class Foo {
+    fun a() {
+        class S
+    }
+}
+
+// TESTED_OBJECT_KIND: function
+// TESTED_OBJECTS: Foo$a$S, <init>
+// FLAGS: ACC_PUBLIC