[fixes #3450] Add support for extension methods on records

test/transform/resource/after-ecj/ExtensionMethodOnRecord.java

@@ -0,0 +1,18 @@
+// version 14:
+import lombok.experimental.ExtensionMethod;
+public @ExtensionMethod(ExtensionMethodOnRecord.Extensions.class) record ExtensionMethodOnRecord() {
+  static class Extensions {
+    Extensions() {
+      super();
+    }
+    public static Integer intValue(String s) {
+      return Integer.valueOf(s);
+    }
+  }
+  public ExtensionMethodOnRecord() {
+    super();
+  }
+  public void test() {
+    ExtensionMethodOnRecord.Extensions.intValue("1");
+  }
+}