8250625: Compiler implementation of Pattern Matching for instanceof (Final)

Reviewed-by: vromero

test/langtools/tools/javac/patterns/PatternVariablesAreNonFinal.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8231827
+ * @summary Pattern variables are non-final.
+ * @compile/fail/ref=PatternVariablesAreNonFinal.out -XDrawDiagnostics PatternVariablesAreNonFinal.java
+ */
+public class PatternVariablesAreNonFinal {
+    public static void main(String[] args) {
+        Object o = 32;
+        if (o instanceof String s) {
+            s = "hello again";
+            new Runnable() {
+                @Override
+                public void run() {
+                    System.err.println(s);
+                }
+            };
+        }
+        System.out.println("test complete");
+    }
+}