Fix JDK 25 LinkageError in JavaUnrestrictedClassLoader (#6736)

Wrap defineClass() in try-catch for LinkageError to handle JDK 25+ class loader constraint violations. When app classloader eagerly loads com.sun.* classes through cross-module type boundaries, fall back to parent delegation instead of crashing.

Co-authored-by: Tim te Beek <tim@mac.home>
Co-authored-by: Claude Haiku 4.5 <noreply@anthropic.com>

Author: 3 people

rewrite-java/src/main/java/org/openrewrite/java/JavaUnrestrictedClassLoader.java

@@ -105,7 +105,18 @@ public Class<?> loadClass(String name) throws ClassNotFoundException {
                         Path classFile = path.resolve(internalName);
                         if (Files.exists(classFile)) {
                             byte[] bytes = Files.readAllBytes(classFile);
-                            return defineClass(name, bytes, 0, bytes.length);
+                            try {
+                                return defineClass(name, bytes, 0, bytes.length);
+                            } catch (LinkageError e) {
+                                // On JDK 25+, cross-module type references in DocCommentTable can cause the
+                                // app classloader to load jdk.compiler classes before this classloader does.
+                                // Fall back to parent delegation for the already-loaded class.
+                                try {
+                                    return super.loadClass(name);
+                                } catch (ClassNotFoundException cnfe) {
+                                    throw e;
+                                }
+                            }
                         }
                     }
                 } catch (IOException e) {