Consider this code:
---
public class PatternTest {
    public static void main(String[] args) {
        Object expr = "a";
        boolean b = expr instanceof (String a && a.equals("a"));
    }
}
---

This crashes javac:
$ javac --enable-preview -source 17 PatternTest.java
Note: PatternTest.java uses preview features of Java SE 17.
Note: Recompile with -Xlint:preview for details.
An exception has occurred in the compiler (17-internal). Please file a bug against the Java compiler via the Java bug reporting page (http://bugreport.java.com) after checking the Bug Database (http://bugs.java.com) for duplicates. Include your program, the following diagnostic, and the parameters passed to the Java compiler in your report. Thank you.
java.lang.NullPointerException: Cannot read field "sym" because "this.lvar[3]" is null
        at jdk.compiler/com.sun.tools.javac.jvm.Code.emitop0(Code.java:577)
        at jdk.compiler/com.sun.tools.javac.jvm.Items$LocalItem.load(Items.java:399)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitSelect(Gen.java:2339)
        at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCFieldAccess.accept(JCTree.java:2450)
...
---