Fix access to private static native functions

compiler/testData/codegen/boxWithStdlib/native/privateStatic.kt

@@ -0,0 +1,24 @@
+import kotlin.jvm.*
+import kotlin.platform.*
+
+class C {
+    class object {
+        private platformStatic native fun foo()
+    }
+
+    fun bar() {
+        foo()
+    }
+}
+
+fun box(): String {
+    try {
+        C().bar()
+        return "Link error expected"
+    }
+    catch (e: java.lang.UnsatisfiedLinkError) {
+        if (e.getMessage() != "C.foo()V") return "Fail 1: " + e.getMessage()
+    }
+
+    return "OK"
+}