Report UNUSED_PARAMETER on main parameter in 1.3+ #KT-26999 Fixed

compiler/testData/diagnostics/tests/smartCasts/inference/kt2851.kt

@@ -1,7 +1,7 @@
 //KT-2851 Type inference failed passing in not-null after smart-cast value in Pair
 package a
 
-fun main(args: Array<String>) {
+fun main() {
     val value: String? = ""
     if (value != null) {
         foo(Pair("val", <!DEBUG_INFO_SMARTCAST!>value<!>))