[FIR] Add UNCHECKED_CAST

Regenerate diagnostics code

compiler/testData/diagnostics/tests/inference/upperBounds/kt2856.fir.kt

@@ -1,20 +0,0 @@
-//KT-2856 Fix the getOrElse signature to be able to return any supertype of V
-package d
-
-import java.util.HashMap
-
-public inline fun <K,V1, V: V1> Map<K,V>.getOrElse1(key: K, defaultValue: ()-> V1) : V1 {
-    if (this.containsKey(key)) {
-        return this.get(key) as V
-    } else {
-        return defaultValue()
-    }
-}
-
-fun main() {
-    val map = HashMap<Int, Int>()
-    println(map.getOrElse1(2, { null })) // Error
-}
-
-//from standard library
-fun println(message : Any?) {}

compiler/testData/diagnostics/tests/inference/upperBounds/kt2856.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 //KT-2856 Fix the getOrElse signature to be able to return any supertype of V
 package d