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

compiler/testData/diagnostics/tests/smartCasts/loops/whileNullAssignToSomething.kt

@@ -1,4 +1,4 @@
-fun main(args: Array<String>) {
+fun main() {
     var result: String? = null
     var i = 0
     while (result == null) {

compiler/testData/diagnostics/tests/smartCasts/loops/whileNullAssignToSomething.txt

@@ -1,3 +1,3 @@
 package
 
-public fun main(/*0*/ args: kotlin.Array<kotlin.String>): kotlin.Unit
+public fun main(): kotlin.Unit