'sealed' is now not 'final' by default + related code changes #KT-10266 Fixed

compiler/testData/diagnostics/tests/smartCasts/openInSealed.kt

@@ -0,0 +1,8 @@
+sealed class My(open val x: Int?) {
+    init {
+        if (x != null) {
+            // Should be error: property is open
+            <!SMARTCAST_IMPOSSIBLE!>x<!>.hashCode()
+        }
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/openInSealed.txt

@@ -0,0 +1,9 @@
+package
+
+public sealed class My {
+    private constructor My(/*0*/ x: kotlin.Int?)
+    public open val x: kotlin.Int?
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}